Aquaponics anyone?

[Guest]

For those that are unfamiliar, aquaponics is simply the combination of fish production (aquaculture) and hydroponics. It is not new, makes complete sense, and seems to be a rather efficient way of growing organically in a hydroponic setup. I am seriously considering upgrading my bio-buckets to an aquaponic system, but I have even less experience raising fish than I do growing hydroponically. The bio-buckets are already basically an aquarium, all I am missing is the fish. I have found a wealth of information on aquaponics on various websites that are non-pot related, but I have found very little info on small scale operations. CW is a decent resource, Breeder Steve of SOL seeds grows this way, but most people use aquarium fish, specifically African Chiclids. I am interested in using catfish in a 350 gallon grow tank and a breeder fathead minnow colony in a 50 gallon tank for supplemental feed. I will feed the catfish fathead minnows, 35+% protein unmedicated fish feed, red wigglers, grasshoppers, and possibly kitchen vegetable matter waste; the minnows will be fed flake food and surface algae that grows on nylon stockings stuffed with worm castings and compost. I will supplement fish waste with aquarium grade K and Fe and dolomitic lime. All water will be supplied by a continous flow, tankless RO system capable of producing 30 gallons per HOUR (GE Merlin model RO system).

Both fish tanks will be fed water from the reservoir and overflow back to the reservoir. I plan on using a fluidized bed filter suitable for a 900 gallon tank for additional biological filtration. Two flower rooms measuring 24 square feet lit by 1000w HPS with 6 plants each. One veg room measuring 16 square feet lit by 800w MH with 6 plants. One mom/clone room lit by 300w MH for 4 moms and 160w fluoros for up to 15 rooting clones. Crops will be rotated every 6 weeks to 2 months depending on strain. This will ensure a minimum of 6plants in flower, 6 in veg, and 4 moms; and a maximum of 12 flower, 6 veg, 4 mom, and 15 clones pulling nutrients from the aquarium effluent. Plant and fish light cycles will be offset by 12 hours to ensure even DO requirements throughout the day. Overall system capacity will be in the neighborhood of 550-600 gallons.

Finally, the questions:
1) Does anyone have any experience with the tank culture of catfish starting at fingerling size of 6-8" and raised to a weight of around 1.5 lbs.?
2) What stocking density should I shoot for to maintain adequate nutrient levels without seriously overcrowding the fish?
3) Has anyone here experimented with aquaponics, and if so, please give a description of your experiences.
4) Any educated advice on fish species, fish feed, aquarium lighting, large aquarium construction, or anything I may have missed will be greatly appreciated.

I encourage anyone interested in aquaponics to first search CW and OG for related threads, there are quite a few pioneers out there, but I haven't run across anyone raising fish for food in their aquaponics setup.

Thanks for all of your help.
NTS

[KRS Juan]

Aquaponics always looked really cool. I once had an extra clone that i squeezed into an opening above my fish-tank (40 gal, cichlids, guarmi's, barbs, and others) and with the roots dangling into the tank. For the first few days it exploded in both plant-growth and root-growth, but then the fish ate all the roots so it died.

I save all the waste water from cleaning the tank and use that on my veg plants, they seem to love it.

Sounds like a very advanced setup your goin for there, good luck and keep up informed.

-KRS Juan-

[Guest]

Along for the ride, very interesting approach.

I read a bit about Aquaponics about a year ago then my enterest fizzled out but this is getting me re-energized

Tex

[Guest]

I always wondered if I shit and Pissed in my Resevoir if that would help. :chin:

That sounds interesting in itself......I used to use my Red Ear Sliders (Turtles) water for Veggin my seedlings till they needed more Nutes. Worked great. I guess my questions would pretty much be the same. More so what kind of fish would be the best to use?

Whatever you find out, please let us know.

Blatant :wave:

[GreatLakes THC]

KRS... My mom's been using fish poop to feed her plants since as long as I can remember. I'm not sure what the name of the stuff is but it's commercially available, and her plants have always looked fantastic.

So let me figure this out,basically it's growing your plants on top of a reservoir that you're growing fish in and using their waste and acceptable supplements that don't harm the fish to nurish your plants through their lifecycle? Sounds like fun, but why would you do that? Do you also plan on eating or marketing the catfish? If you're of the school of thought that flushing is necessary prior to harvest would this system eliminate the need for a flush?

GreatLakes THC :chin:

[Guest]

Thank you all for showing interest, I am still in the concept phase, but I am 80% sure I will go through with this. I will try and put together a basic post of everything I have found out so far, so we can all learn together.

-Blatant- what kind of fish would be the best to use?

Breeder Steve has found African Cichlids to be the best for marijuana aquaponics due to their tolerance of slightly saline water conditions and relatively low (for aquariums) pH of 6.5 and temp of 70F. But he is most familiar with aquarium fish. I am interested in using food fish and originally looked at tilapia, but they are a specially controlled species here and in much of the south where it doesn't get cold enough in the winter to kill them off in the wild. I have since changed to either channel catfish or bluegill. I think bluegill would be easier, but I would prefer to go with catfish if possible for culinary reasons.

-Great Lakes -So let me figure this out,basically it's growing your plants on top of a reservoir that you're growing fish in and using their waste and acceptable supplements that don't harm the fish to nurish your plants through their lifecycle?

Some people have tried putting fish directly in the same container as the plants, but there are very few fish that aren't tempted by those delicious roots, so most people seperate the two. Imagine the fish tank as being one HUGE tubbler that is added to a constantly recirculating DWC setup.

-Sounds like fun, but why would you do that?

Why not? Can you guarantee those nutrients you pay $30 a gallon for are organic. I can guarantee the fish feed that I pay $15 for 50 POUNDS is organic. I control the entire ecological loop. Another point, as with other very mild organic fertilizers, fish effluent can not burn your plants! You either have too little nutrients, in which case you increase fish feeding; or you have too few plants to draw off the excess nutrients and the fish begin to suffer. In this case you do a partial water changeout just like a normal aquarium. Aquaponics is however completely opposite of my current grow in regards to daily maintenance. With bio-buckets, I visit my grow once a week. Aquaponics will require twice daily maintenance, and a move on my part. That is why I am still only 80% sure I am going to do this.

-If you're of the school of thought that flushing is necessary prior to harvest would this system eliminate the need for a flush?

Truth be told, I don't flush right now anyway. From what I understand, from those who claim a flush is necessary, this removes built up salts and chemicals in the vegetable matter of the plant. True organics uses little or no salts, therefor no build up, and no need to flush.

I will begin putting together everything I have found out so far, will return shortly. Please keep questions coming, they help me learn too.

NTS

[Guest]

Aquaponics actually predates what we know as hydroponics. Most sources that quote ancient Aztecs or Egyptians growing plants on floating mats in lakes or rivers are actually describing aquaponics, not hydroponics as we know it today. The nutrient solution in aquaponics is not artificially applied, rather it is the effluent, or waste run-off, of the fish. Aquaponics on a scale that we would use could be thought of as an overgrown, overly complicated aquarium where we are more concerned with the growth of the plants than we are the growth of the fish. To protect the plants root systems, we remove them from the aquarium and place them in a seperate container with fish effluent being cycled through the plant containers and back to the aquarium.

Basics of Aquariums

First of all, we are only dealing with fresh water fish. Some may mistakenly think, my hydro nutes contain salts, the ocean is salty, I should be able to keep a marine tank in aquaponics. The primary salt necessary for marine life is sodium chloride, table salt. This salt happens to be toxic to marijuana, and most land-based plants, at the levels required by marine life, so fresh water fish are used.

Most waste that accumulates in aquariums is composed of dissolved carbon dioxide, urea, ammonia, and organic matter from uneaten food and fish poop. Carbon dioxide is released in the same manner as dissolved oxygen is replenished - through aeration. Urea and ammonia, which are highly toxic to fish at low levels, are converted to nitrates, which are slightly toxic at high levels, by bacteria living in a biological filter. Organic matter is removed by filtration and further breakdown by bacteria in the bio-filter. Excess nitrates are removed by plants or by frequent partial water changes.

Note: Fish are delicate living organisms. Please don't use the above overly simplified explanation of aquariams as an instruction manual on how to keep fish. You will likely end up rapidly killing all of your fish. Aquariums are tiny ecosystems that must be set-up and maintained correctly to avoid mass fish homicide.

Combining Aquaculture and Hydroponics
Commercial vegetable greenhouses require massive amounts of nitrate rich water soluble nutrient solutions for their plants. Commercial fish producers require a way to dispose of massive amounts of nitrate rich, nutrient laden, water. See the connection? So did fish producers a few decades ago.

Some indoor marijuana growers already familiar with hydroponics have also realised this. At OG, you will find aquaponics in with the organic hydro forum. At CW, most aquaponics info is found in the soil&organics forum or in the Spice of Life seeds help desk. Unfortunately for me, most marijuana growers using aquaponics use regular aquarium fish rather than edible fish and grow on a much smaller scale than I am planning.

Marijuana specific aquaponics
Note: None of these observations are mine, I have not tried anything yet!

Marijuana needs less nutrients than most vegetable plants, like tomatoes and corn, but needs more nutrients than green leafy vegetables like lettuce. Most commercial aquaponics growers stick with low nutrient plants like lettuce to avoid insufficient nutrient levels for growth. Marijuana grown to harvest in an aquaponic system requires a higher stocking density than normal in an aquarium in order to produce enough fish waste to feed the plants. Also, marijuana requires a supplement of aquarium safe iron and potassium. High protein, high quality fish feed will produce enough micro nutrients and nitrates for marijuana cultivation. Breeder Steve has found that the broader a diet you can offer the fish, the wider a range of micro nutrients you will end up with. He also found that uneaten fish pellets tend to impart a fishy flavor to marijuana, so he recommends supplementing or entirely eliminating fish feed pellets if possible and using only live or frozen feed like minnows, brine shrimp, worms, etc. He also grows using ebb and flow, not DWC. Basically any hydro system can be adopted to aquaponics, but aeroponics may have problems due to clogging. Effluent must be filtered prior to reaching the plants, otherwise organic matter may mat up in the roots and cause small localized anaerobic conditions. We all know what that means. Breeder Steve has found that with a high enough fish population, it is actually preferable to have plants at different stages drawing off of the same reservoir. Flowering plants have different nutrient requirements from rooting clones, and combining all stages of growth helps to fully deplete fish waste build-up. Simple aquarium test kits ($50US or less) can be used to monitor N levels. Expensive aquaponics test kits ($800US or more) can be used to monitor all NPK levels and most micronutrients. As with all true organics, TDS pens are useless. pH should stabilize around 6.5, and water temps should be maintained as close to 80 degrees as possible. Most people find 70 degrees to be a good compromise between what the plants need and what the fish want. All nutrient overdoses are impossible as the fish will die before the plants do. All solid nutrient additions (other than fish feed) are added in lengths of nylon stockings. N deficiencies are corrected by increasing fish feeding, P def. corrected by adding rock phosphate, K def. corrected by adding K supplement for aquarium plants, Ca def - add dolomite lime, Mg def - add Epsom, Fe def - add Fe supplement for aquarium plants. No other deficiencies should ever be noted if you are using high quality, high protein fish feed. Single plant deficiencies are treated using foliar sprays. All additives and foliar sprays must be safe for fish. In one way, aquaponics forces you to go truly organic, although some people have claimed to get away with adding small levels of GH Micro or other hydro nutes for supplemental nutrients.

Links:
Aquaponics Journal - Commercial system periodical with lots of helpful info
http://www.aquaponicsjournal.com/articles.htm

Robyn's Pond Page - VERY useful info on small landscaping ponds and fish management and care. We are basically setting up a small, indoor pond so this site was very useful for ideas.
http://www.fishpondinfo.com/pond.htm

SRAC Fact Sheets - Southern Regional Aquaculture Center commercial system info
http://srac.tamu.edu/

The Krib - Everything you ever wanted to know about aquariums
http://www.thekrib.com/

Aquaponics- Ever Try It" - Thread at OG by Breeder Steve
http://www.overgrow.com/edge/showthread.php?threadid=9716

Homegrown Organics - Thread at CW by ceteris paribus
http://cannabisworld.org/vbportal/forums/showthread.php?s=&threadid=79227&perpage=15&pagenumber=1

Aquaponics... - Thread at CW by 10k and Breeder Steve
http://cannabisworld.org/vbportal/forums/showthread.php?s=&threadid=33169&highlight=aquaponics

I have enough bookmarks on aquaponics to fill an entire thread, so I'll stop there for now. Searching on the internet rapidly became unproductive because there are so few people doing this on a "hobby" instead of "commercial" level. Please ask any questions you may have, if I don't know the answer, I will be forced to look it up and therefor learn as well.

On another note, I have been chastised in the past for not posting pictures. I have not felt that I had enough experience to justify the risk, but if I get this working then I might need to re-evaluate that feeling. I am not very computer literate, so if anyone could pm me on how to post pics safely from my end it would be greatly appreciated. Either way, I am still in the concept phase, and it will be a number of months before I feel comfortable with spending the amount of money I will need to in order to put this system together.

[Guest]

funnily enough, I was discussing this with a buddy of mine. He said that in the past most people have used eithre koi (tho not recommended because they give off LOTS of ammonia, and Tilapia (these are soft water african cichlids, the majority of the african cichlids for sale in your local pet store are going to be a mix of Lake Tanganyka species , Lake Malawi species, and Jewel Cichlids.) NOw lets start diggin into my fish archives (I happen to breed South American cichlids, and used to run the fish room at the local pet store. I will post some photos of my tabnks later if anyone is interested. Anyways, the fish that are better suited to the aquaponics set-up from my experience breeding and keeping fish would be either guppies or platies, with the platies I would go with Xiphorus varietus as they are more tolerant of cooler water temps. Both species can also be kept in very crowded spaces. As far as diet goes for the guppies/platies, you could feed them a varied diet of blanched spinach/peas, algae wafers, red wigglers, maybe spirulina, but I would go with Spirulina from the grocery store over the pet store. I would recommend staying from prepared flake or pellet foods as they have a warning on the side saying not to feed to fish that are intended as food ( which although you arent eating the fish, the plants are 'eating' thier decomposing bodies), so I wouldnt want any nasties that may be in the food going into the plants. Another reason to get the platies/guppies over other species of fish is that they eat algae, and not just living organisms so there is no need to add an algae eater to the tank. Also be prepared for at least 25% of the fish to die before your even done the crop, as you have to pack the in the tanks so tight you could 'walk' on thier backs. I will talk to my buddy within the next few days and get more info for ya, as this is his prefered method of growing. Hope that helps.

[Guest]

oh and the main reason to stay away from the african cichlids aside from Tilapia is that they require a pH of 8-9 depending on species. Do a google search and it will confirm it for ya.

[GreatLakes THC]

Here's a question for you smarties. and I mean that respectfully. For hydroponic growing the best pH range is 5.6-6.2 depending on what you've read, but most people will say that 5.6-5.8 is the best. The reason being that at different pH levels different nutrients become available, blah blah blah. If you have to keep the solution at a higher pH for the fish to survive, will this not effect what nutrients are available for uptake by the plants?

Fascinating concepts

GreatLakes THC

[Guest]

I am sure it would, which is why I only recommend Central-South American fish really, as they have a pH range between 4.5-7.0, depending on species. I think it may be a possibility to try this with some of the cooler water apistogramma cichlid species, as so long as there is suffecient leaf litter you can really really pack them in there. Dr. Uwe Romer has reported finding up to approx. 1000 apsitogrammas living within a m2, but there was somewhere around 3 feet of leaf litter. I would actually be interested in seeing some south and central american landraces grown with an aquaponics system containing fish from the area said plants came from, could be pretty interesting.

[Guest]

Bram, like I said, I know nothing about aquariums or fish, just what I've read. There are numerous people doing aquaponics with aquarium fish, if I remember correctly Breeder Steve used African Cichlids, but I am looking to use edible fish. Tilapia is not an option in my location, I am considering either bluegill or catfish.

As to the pH issue... I too am not entirely sure. Breeder Steve and others say that basically all chemical hydro knowledge you know should be thrown out the window when you use aquaponics. I know that Hurtback had said that bio-buckets are able to run at a higher pH than normal, although I haven't tried it in my bio-buckets as high as 6.5. Perhaps it has something to do with the bacteria in the system and how the plants in organic growing doen't necessarily absorb raw nutrients but rather organic compounds that are the waste products of bacteria living in their root system. Due not quote me on this. TK may be able to explain.

NTS

[Guest]

To the surprise of my fish dealer I keep fish together that theoretically won't live together due to differing PH preferences, ie hardwater cichlids from some of the best ganja producing lands in Africa, (calcium rich soils around Lakes Malawi, and Tanginyka, PH 7.1) These hardy fish do quite well in a tank with southeast asian and amazonian varieties that prefer something around PH 6. In general the grass likes 6.2. I let it move around a little because in my superstitious mind that allows the freeing up of things I barely understand. If it has risen to the high sixes I will bring it down, even with apple juice or coffee, unless I feel it needs a boost of fert, then I give it a tbsp of EJ Catalyst as I mentioned earlier.

http://www.overgrow.com/edge/showthread.php?threadid=9716

[Guest]

just so you know, keeping your africans with the asians/sth americans can lead to multiple varietys of disease, with ich being the least you have to worry about, not to mention the possibility of unwanted and unnatural hybrids. A good example being the Flowerhorn/Luo Han for the hybridization bit.

[cough_cough_eer]

but I am looking to use edible fish. Tilapia is not an option in my location, I am considering either bluegill or catfish.


I have no experience aquaponics but catfish are bottom feeders so(I'm thinkin) if you provide plenty of food for them at the bottom, perhaps they will leave your plants alone. Are you planning on building a pond for these fish? I dont know the requirements for keeping catfish, but they probably need a preety big pond.

As far as tank raised fish I think Bram might be on to something with the guppies or plattys.

Question??/ could guppys or Plattys be kept in an outside pond. How sensitive are they to cold water?

[Guest]

The Channel catfish acts more like a trout. They'll feed at any depth and can be caught with artificial crankbaits.

The catfish farmers in Mississippi raise channel cats and feed them grain. Keep them plump and happy and they won't eat your minnows...lol. :yummy:

Forgot to say that the farmers stock the ponds with 4-6 inch fingerlings and harvest 2-3 pounders in two years. That'll give you an idea of growth rate.

[Guest]

Bram - have you or a friend ever made a large aquarium out of either plywood or acrylic yourself? I am looking for ideas for my large grow out tank since I don't feel like spending a couple thousand for a manufactured acrylic tank. I have seen plans for smaller ply tanks with glass fronts, coated with Epoxide HS Tank Lining by Sherwin Williams, but the plans were for 30" high or less. I'm looking at 48" deep. Plans called for 3/4" ply construction, I was thinking of doubling two sheets of 3/4" or constructing a 16" on center 2 by 4 stud walls with 1/2" ply walls. I know 2 by 4 will be stronger, but I will also lose 8" of length on each side - on a 4' by 4' by 4' tank thats considerable, somewhere around 120 gallons. Obviously you can see why I would rather go with 1.5" thick walls if I can. I just don't want 350 gallons of water and 100 flopping fish on my floor. There are approx 7.5 gallons of water in a cubic foot, at 8 pounds per gallon thats 60 pounds per square foot at one foot deep, or 240 pounds per square foot at 4 feet deep. I think double thickness of 3/4" ply will be ok, but I would much rather hear it from someone who knows.

Also, what do you know about fluidized bed filters such as this: http://www.marinedepot.com/md_viewItem.asp?idproduct=RB76 91 . Would this be truly sufficient for biological filtration?

Thanks again for you help and clarification.
NTS

[Guest]

Spankin Elvis - Have you ever heard of anyone raising channel cats in raceways or large tanks rather than ponds? Also, the feeder fathead minnows will be kept in a seperate 50 gallon tank, until its feeding time for the cats, then I'll pick out a few lucky minnows and throw them in with the catfish. Another question, do you think I'll have problems with catfish trying to jump out of the tank? I ruled out bass for this reason. Also, I like the taste of catfish better anyway. I only plan on growing them out until they're about 1.5 pounds, or about a year. I plan on stocking with x number of fingerlings initially, and then restocking with that same number every 6 months. By the end of the year, I will have 3x catfish stocked with approximately 1/3 each at fingerling, 3/4 pound, and 1.5 pound. I will periodically harvest the 1.5 pounders over six months and replace them with fingerlings to maintain approximately the same biological load on the system. My local supplier stocks 6 to 8" fingerlings. Do you think 1.5 pound, well fed cats will leave 6-8" fingerlings alone in a tank? Or should I design three seperate grow out tanks and keep each "generation" seperate?

Too many questions...

NTS

[Guest]

NS- A far as building a tank goes, I like the sounds of your plywood thing, but for the liner, I would go with super thick pond liner from your local garden store. Get the stuff thats at least 1/4" thick, the catfish will have a hard time puncturing it with thier spines if they get a bit rowdy. As far as keeping fingerlings with a 1.5 lb cat, well this is how a catfishes brain works basically, if its hungry and it sees something that will fit in its mouth; it eats it. I would recommend against the filter you mentioned as well as this will remove alot of the ammonia, which means you will have really low nitrate levels, which is fine during the flowering stage, but I wouldnt use the filter during veg.

Cough- I would try either the Varietus platy (there are two types:varietus and maculatus, with the maculatus being more tropical) or some Texas Cichlids (I understand you guys call them perch down there because alot of underprivliged people fish them from the Rio Grande) For the cichlids easiest location point to get freee ones from would be the Rio Grande and tributaries, the varietus platies would be in the Rio Grande as well most likely (both are native texan fish). If there are none in the Rio Grande look in streams close to the mexican border. Or if its all being done outside and you wanna get rid of misquitos at the same time, I would add Gambusia aka Misquitofish to the pond.

[Guest]

Bram - Forgive my ignorance, I am trying to learn. How does the fluidized bed filter remove ammonia? I thought the sand in the filter was just a colonization point for nitrosomonas and nitrobacter bacteria that eventually convert the ammonia to nitrate. This nitrate remains in the water doesn't it? If not, should I consider using a wet/dry filter, or what type of filter would you recommend? I was originally atracted to the fluidized bed filter due to its small size relative to other bio-filters that can handle the same volume. Is there a comperably sized alternative that will not remove ammonia from the system?

Also, on the pond liner, I chose the two-part epoxy because I was under the impression that this was more durable than pond liner. I originally had planned on using pond liner, as it is cheaper and much easier to work with. Do you know anyone that has used a two-part epoxy to seal a wooden tank? I would rather use a pond liner, but I am looking for the most durability.

Thanks

[Guest]

I dont know anyone who used wooden tanks, but all the garden stores around here have the plywood box built like you were talking about, and they just put pond liner in it. I only recommended the pond liner, because ime the thick stuff actually can repel tree roots. Example, my grandma lined her pond with thin shit that was like 1/8" thick, held the water but within about 6 months the dogwood trees on the edge of her property had sent thier roots throguh the liner, we drained the pond, hacked back the roots put in a 1/4" thick liner and no problems since. As for adding a filter, I would try it without one, just have lots and lots and lots of oxy being pumped into the water.

[Guest]

Bram - I've got more aquarium questions if you don't mind.

I stopped by the local pet store today and had a chat with the aquarium manager. He suggested I use anacharis in the minnow tank because it is a heavy nitrogen feeder and tender enough for the minnows to graze on it. But I have been warned to be weary of the average aquarium shop clerk. Would you agree with his assertion? Also, do you have any experience with algae eating fresh water shrimp? These would be placed in the same tank as the minnows (if the minnows won't eat them) and I would prefer to have a species that could expect to successfully reproduce in the tank. This would allow me to use shrimp as a food supplement for the cats as well, but if they can't breed, they would still make a nice addition to the feeder tank as long as the minnows don't gobble them up. What about African Dwarf or African Claw frogs? Snails? I am looking for a broad range of aquatic life for the 50 gallon tank, but I want only herbivores, the minnows are earmarked as catfish feed only.

Please take a look at my similar thread at CW, the link is in my sig. I am having an interesting discussion with one of the members there and would value your input as well. We are discussing tank size and stocking density, as well as nutrient availability in aquaponics. And if you ever get tired of my constant questioning, please take it as flattery and tell me to shut up.

NTS

[Guest]

Have you ever heard of anyone raising channel cats in raceways or large tanks rather than ponds?

I've seen them raised in large tanks. They seemed to do quite well.

Another question, do you think I'll have problems with catfish trying to jump out of the tank?

No problem there, they're not jumpers, but they will feed off grain floating on the surface.

Do you think 1.5 pound, well fed cats will leave 6-8" fingerlings alone in a tank?

Yeah......6-8" fingerlings should be ok. They have those stinging fins behind the gills to discourage bigger fish.

Good luck with this.....sounds like a cool idea.

[Guest]

Yeah......6-8" fingerlings should be ok. They have those stinging fins behind the gills to discourage bigger fish.

Good luck with this.....sounds like a cool idea.

I figured as much, but I had gotten contrary warnings from a few people so I thought I might ask the opinion of someone who had handled them before. I learned at a young age that the only proper way to grab a catfish usually involves the sole of a boot. Regardless, I am now planning a 2x8 tank instead of 4x4, as this will allow me to use dividers to seperate generations of catfish if there is a problem.

I'm excited too, the more I think about it, the more plausible it seems. I want to get one more grow under my belt in my bio-buckets to make sure I have that end of it ironed out before I throw in the fish. Then there's the move... but I hope to start construction in a couple months.

[Guest]

the minnows shouldnt eat the shrimp, but they cannot reproduce in freshwater, the eggs and larvae have to develop in brackish water. The anacharis is good for N as it grows very rapidly. MInd you the high N water would make great seedling tea. as for fish questions, hell I just wish people would ask me as many questons about pot around here as you do fish. Then people might realise I am not just talking out of my ass, I just dont have the opportunity to grow at the moment so I cant post pics. The whole reason I started coming here was to share knowledge, and knowldge can only be shared when questions are asked, so ask away NTS.

[Guest]

Interesting update: after doing more research, and with the direction of some people at CW, I have come up with a theoretical "stocking density" for growing marijuana with aquaponics. I say theoretical because I have yet to try it. If you are interested, please read the entire thread. The link is in my sig. The coversation, while only one page, goes too indepth to cut and paste here in one post. Please share your thoughts.


So in conclusion, finally:

1. In hydroponics, we are concerned with the total amount of nutrients in the system, not the concentration of those nutrients. Most hydro users have a nearly consistent ratio of solution in the reservoir compared to solution in the entire system, because most people try to keep the reservoir as small as possible without adversely effecting the hydro system. Because of this, we are able to use the Lucas formula to accurately add the correct amount of nutrients to the system even though we are measuring the concentration as TDS. If someone with a 250 gallon reservoir and 300 gallon total system capacity used the Lucas formula specifically as prescribed (0-8-16 per gallon), they would nuke their plants.

2. Because I am growing fish in order to grow plants, the weight of fish required to produce enough nutrients for my garden must be determined, not the weight of fish per gallon of tank as is done when you are growing plants in order to grow fish.

3. This is the sticky part. In S & S Aqua's setup, they need .5333 cubic feet of grow medium for every pound of fish. This translates loosely to .5333 square feet of garden per pound of fish if both fish and plants are harvested perpetually. That makes it 40 pounds of fish for my 76 square foot garden. While by no means accurate, this is a decent starting point for marijuana growers.

Fallacies of #3

- They grow tilapia, I grow catfish. Well fed tilapia and catfish both put on about 1.5 pounds their first year after fingerling stage, but the tilapia does it while only eating 1.5 pounds of feed, where as the catfish needs 3 pounds of feed or more. This implies that 1 pound of catfish produces more nutrients (through its waste) than one pound of tilapia, bringing fish count lower than 40 pounds. However, tilapia gets a good portion of its diet from eating algae, but in my system, catfish don't eat algae, what little algae I will allow (hopefully) will be eaten by minnows, who will then in turn be eaten by catfish. This leans us back to the original 40 pound estimate.
- They grow mostly lettuce, I grow marijuana and a handful of aquatic plants and perhaps some lettuce. Marijuana's phosphate needs are higher in relation to its nitrogen needs when compared to leafy vegetables like lettuce. Organic phosphate sources that do not contain nitrogen are hard to find, I can only think of rock phosphate, a very slow release, non-renewable resource. I believe it will be easier to raise total nutrient input in order to get adequate phosphate, and then deal with excess nitrogen, rather than raise available phosphate WITHOUT creating pea soup. Because of this, I may need more than 40 pounds of fish.
- Due to inadequate access to mass spectrographs, I will never be able to adequately ensure that micro nutrients are not building up to toxic levels through testing of the nutrient solution. To combat this, I will need to do partial water changes (perhaps 5% every two weeks, 100% every two years), and in so doing, I will lose nutrients in the water I remove. This will tend to push my 40 pound estimate up.
- I'm sure there's more, but no estimate is perfect.

OK - I need professional criticism, am I on the right track, or am I about to plan the death of countless fish and priceless bud?

NTS

[Guest]

my buddy was saying that you need to put some stuff in a nylon bag and throw in the water too for phospahtes and shit, cant remember what all he said to throw in there; but I have to take him a bunch of fish water soon, so I will get him to right it down for me.

[Guest]

It's been a while, and I feel like I have learned quite a bit. A lot of time was spent searching past the 30th page of a google search and diving into five year old archives at CW.

First, the most important (to me) point raised in this thread. I had mentioned concerns about internet security. I live in the United States, and as such, I must answer to the whims of the majority. Because I would rather not spend a moment in jail, I have to take certain precautions while conversing online. But, I am barely able to tell the difference between my computer and that large rock with my address painted on the front that lies at the end of my driveway. In the security forum of CW, who the kid has a few very understandable threads about internet security. I highly suggest that all who are in a political position similar to mine read those threads. Due to his advice, I will most likely be changing my IC Mag nickname. I have not yet determined if this is necessary, but if it is, I look forward to continuing our relationship under another name.

Second, as to the point of this thread, I have quite a bit to share about aquaponics. This is, of course, entirely second hand information, as I have yet to try this out. If you are as interested in the subject as I am, then read on.

Treating Fish Effluent
There are two main schools of thought on how to run an aquaponics system, only one is suitable to marijuana growing. The first, and most common, involves removing the solid fish waste from the system via settling tanks. This is beneficial because solid organic compounds will get caught in the roots of DWC grown plants and decompose, causing small zones of anaerobic bacteria growth that can quickly wreck a hydroponic system. Because DWC is the easiest way to grow hydroponically (on a large-scale commercial vegetable grow, I am not implying anything in regards to our hobby by this statement), most aquaponics growers remove the solid waste and are left with a nitrate rich, micronutrient poor nutrient solution. This method is only suitable in growing green leafy vegetables like lettuce, not our favorite herb, and therefor should be discarded. The second approach involves huge bio-filters that are capable of trapping and growing bacteria that break down the solid fish waste. These commercial systems are rare, but they do a nice job of growing higher plants like tomatoes. Marijuana's non-nitrogen nutrient requirements are larger than lettuce, but less than tomatoes, so following the second approach should be best. One example of this on a legal, commercial scale, is S & S Aqua Farms. They advocate two cubic feet of growing medium to every one cubic foot of fish tank water. This formula works for them because they try to grow the maximum amount of fish possible in a given tank size, and their grow medium acts as the sole biological filter for the system. We, however, don't care about fish production. If you assume excess bio-filtration and 2% of fish weight in feed per day, then their formula roughly converts to .5333 square feet of garden per pound of fish. But this is at maximum stocking levels. I plan on increasing the fish grow out tank size by a factor of 3, providing more room and less stress for the fish, and in turn, a healthier system. This figure is approximate and will need to be fine tuned in each individual system due to differing nutritional values of feed, different nutrient requirements of fish, etc.

Please note that this implies that we need to focus on the stocking weight of fish per square foot of garden, not stocking weight of fish per gallon of water in the grow-out tank. Plants do not consume nutrients by concentration, but rather by total amount available. Most hydro systems get away with reporting the amount of nutrients per gallon (as TDS) because nearly all hydro users have a small amount of nutrient solution compared to plant needs. Take my current grow for example. I have six plants in flower in a 4x6 space under 1000w with approx. 45 gallons of water in the system. If I hypothetically convert to aquaponics with a 90 gallon tank, I would increase system capacity to 135 gallons, but I would not be increasing the plant's nutrient requirements. This means that nutrient concentration would need to decrease by 2/3, but total nutrient availability would remain the same.

Algae Insurance
This is the area I need the most help in. I have no experience with aquariums, so all input is greatly appreciated. Higher plants (cannabis and anachris in my situation) are able to out-compete algae in one and only one area, phosphorous uptake. As long as phosphorous is the limiting nutrient in solution, algae will not flourish. If, however, there is an excess of phosphorous (i.e. an amount available greater than the amount that higher plants can use), algae will bloom. In normal hydro, algae isn't a problem because light can be removed from the nutrient solution, precluding algae growth. In an aquaponic system, the fish and aquatic plants must have light, so light exclusion is not a possible way of controlling algae growth. P limiting is all we are left with. But, our favorite herb requires P to flower. Uncontrolled algal growth will cause decreased DO levels due to decomposition and anaerobic zones if the algae is trapped in the root zone of the plants. All bad. Excess P increases the likelyhood of an algal bloom, so P must be added to the system at the amount required by the marijuana plants, not too far above. In aquaponics, nitrogen is already in excess (see below), and there are few organic P sources that don't also add N. For that reason, I am going to try to regulate fish feeding by primarily monitoring P levels, I will feed as much as possible while still ensuring that there is no excess of P in solution. If this won't control algae, then it's back to the drawing boards, but I am pretty sure that I am on the right track.

Nitrogen Toxicity
What? I previously said that you can't fertilizer burn plants in aquaponics. Well, I was half right. Interestingly enough, this also has implications in the great flush before harvest debate. In aquaponics, N can not build up to plant toxic levels before negatively affecting the fish. But, for marijuana, excess nitrogen in flower produces more "leafiness", which while not toxic to the plant, certainly isn't desireable. Which would you rather have - twenty ounces of plant matter and five ounces of bud, or twenty-five ounces of plant matter and five ounces of bud? The majority of fish waste (excluding CO2) is urea and ammonia, NH2 and NH4. These are highly toxic to fish, but readily convert to nitrates in a cycled aquarium and are easily absorbed by plants. Herein lies the problem. Most plants, marijuana in particular, absorb nitrogen easily, but marijuana in flower will still uptake nitrogen at levels far higher than optimum, while still being below toxic levels. If my phosphorous limiting plan works, this means I will have an excess of nitrates, and I will need to remove these nitrates to prevent excessive leafiness in my flowering plants. I plan to do this by growing anacharis in the minnow tank and lettuce in a constant drip/NFT type of system above the catfish tank. I have changed my catfish tank plans to a 2x8 foot tank rather than 4x4, because this will make it easier to divide the tank into smaller sections for different ages of catfish if that proves to be necessary. I have also found some 10.5" x 28" x 8" deep plastic planters that would be excellent in growing lettuce and leafy herbs like marjoram and cilantro, these will fit nicely if I place four planters over a little more than half of the catfish tank. The light overflow will be enough to maintain the catfish's biological clock, while hopefully being insufficient for algae growth. Any roots that extend beyond the planter and grow down into the catfish tank may be looked upon as an excellent meal by the catfish, but I don't mind. They aren't destroying the good herb. All vegetables grown MUST be removed from the system, otherwise the excess nitrogen remains in the loop. There is one other solution to the excess nitrogen problem that I feel I must disclose, however I highly recommend against it. If you were to provide an area that is seperate from your fish and plant grow areas, but still plumbed into the system, and you ensured that this area had the ability to harbor anaerobic bacteria, you might be able to harness the ability of some anaerobic bacteria to convert nitrate into gaseous nitrogen, which would be degassed and removed from the system. The problem with this method is that lots of really, really bad bacteria also love the same environment as the denitrifying bacteria, and if you aren't careful you could be growing some really nasty crap. Perhaps this method would be more suitable to those with terrorist leanings, I for one do not plan on testing biological agents on myself.

Stocking Density
I have touched on this before, but it won't hurt to emphasize this again. If you are doing aquaponics in order to grow plants, you should focus on the stocking weight of fish per area of plant growth, not stocking weight per gallon. I can grow the same amount of marijuana off of 40 pounds of fish in an 80 gallon aquarium as I can 40 pounds of fish in a 320 gallon aquarium. The less crowded your fish are, the better you are. Plus, excess tank capacity allows for increasing the fish weight and therefor plant draw off of the system. Do not focus on number of fish per gallon, instead focus on weight of fish (or more appropriately, weight of fish feed) per square feet of growing area.

Nutrient Management
Following Breeder Steve's advice, I plan on limiting manufactured fish food input in order to limit off flavors in the marijuana. The issue of human consumption of fish raised on store bought fish food has been raised. Please note that I am planning on buying all manufactured feed from an agricultural source that sells fish feed that is specifically designed for eventual human consumption. Also, I will stay away from feed that is fortified with antibiotics. Overuse of antibiotics is a whole 'nother story, I will save you the trouble and not get side-tracked. The earthworms that I plan on raising to make up a portion of the catfish feed will be fed un-medicated chicken layer mash. The beauty of aquaponics is how you can control the individual organic components that eventually make up your nutrient solution. I have found a local source of mushroom compost that will also serve to feed the earthworms and the minnows, plus organic free-range chicken manure, horse manure, plus I plan to use catfish filleting waste and bat droppings from my (soon to be inhabited I hope) bathouse. Organic nutrients are plentiful, if you do some homework, and if composted, they can be added directly to the system in nylon stocking "tea bags" that grow algae that feeds the minnows that feeds the catfish that feeds the marijuana. It's awesome, but I am getting carried away.

Another issue is sodium buildup. Most manufactured fish feeds are high in sodium, and if relied upon heavily, they will result in a nutrient solution with toxic levels of sodium. Live feed such as grasshoppers, earthworms, and red wigglers will help to lower sodium inputs, but generally speaking, sodium will be the first element that will show up in toxic levels in an aquaponic solution. Regular water changes will reduce this threat, but water changes reduce all nutrient levels. This is yet another reason to stay away from manufactured fish feed.

Finally, as to pH levels, this is where I am still the most uncertain. Common wisdom says that 5.2 to 5.8 is optimal for marijuana. However, if you look back to really old posts at OG and CW, they said pH should be between 5.5 and 6.5. Who is correct, I would assume the later recommendations of 5.2 to 5.8 to be more accurate. But this implies that five years ago people were growing in 6.0 + without too many problems. I don't know, I wasn't growing then. I have noticed major problems in late veg and early flower in DWC if pH gets above the mid sixes, but I grow chemically in GH Lucas formula right now. I must confess that I have very little experience with organic growing, whether it be in hydro or soil, marijuana or vegetables. I do not know why 6.5 in aquaponics is OK but 6.5 in chemical hydro is bad. I suspect it has something to do with organic hydro using basic organic compounds rather than elemental compounds, but I am in no position to affirmatively say anything. All I can say is that from other people's reported experience, pH levels in aquaponics should naturally level out between 6.0 and 6.5 and remain there. How this affects the plants... I do not know.

Grow-out tank construction
I haven't completely decided on this yet. I know I am not paying more than $2000 for an acrylic aquarium of comparable size. I believe I can build a 2' x 8' x 3' high plywood tank for about $500. I plan on using both the aquarium safe 2-part epoxy and a couple layers of pond liner. Anything to prevent 500 some odd gallons of water and a good handful of dead fish on the floor. Bulkhead fittings and other regular aquarium erotica is relatively hard to find in my local area, but all can be purchased online. www.marinedepot.com is an excellent site to start off with, they are not always the cheapest, but they do carry a large assortment of aquarium supplies.

Grow room design
All stages of marijuana plant-life must be included in the same aquaponics system. Rooting clones and vegging plants require different elemental nutrient levels than flowering plants. A perpetual harvest will ensure a relatively even nutrient draw, while a perpetual "harvest" of the fish will ensure a relatively even nutrient input. The aim is to shoot for equilibrium. Please remember, however, that you must account for periodic water changes of 5 - 10 percent every two weeks in order to prevent toxic buildup of micro nutrients. This water changeout must be done regardless of testable nutrient levels, so fish load should be slightly higher than calculated in order to compensate. There is evidence that plants can uptake some micro-nutrients, specifically manganese, very readily. Because these micronutrients are needed in such low amounts, toxic levels can quickly be reached if no water changes are carried out. It should be noted that this statement does not apply to most hydro systems, because the amount of micro nutrient buildup potential is so small. The larger your entire system is, the greater the potential for toxic micro-nutrient buildup is. THIS IS AN EDUCATED GUESS, not based on verifiable data. My reasoning is, the more "impure" water you bring into the system, the more "contaminents" you have in that system. When in doubt, differ to the aquarium enthusiast, as the fish are more delicate than the plants. Most people find that an initial fill with de-chlorinated tap water followed by top-offs of RO water to be best for the fish. If you are blessed to live in an area that has extremely poor tap water, than straight RO water will be needed with the addition of dolomite lime for pH stability.

Water Chemistry Makeup and Fish Selection
Most aquaponic marijuana growers at CW follow Breeder Steve's advice and use African Cichlids (or is it chiclids, I can't ever remember). This isn't to say that this fish species is correct, in fact, Breeder Steve uses a whole range of species, African Cichlids being the most common. His take is that they can survive and even thrive at the relatively low pH of 6.0 to 6.5. They do require a higher pH to display their typical colors however, so if you are raising them in order to sell back to the pet store, you need to provide for a tank that is seperate from the aquaponics system where you can gradually raise the pH to 7 or 8 so that they will be more marketable. When it comes to edible fish in a marijuana aquaponics grow, I haven't seen an example yet. I plan on using catfish only because I can not use tilapia. Based on my research, tilapia would be a better choice because they can filter out algae. They are also more efficient at converting feed to weight, but this may actually be detrimental if your sole point of running an aquaponic system is in order to grow marijuana. The wider a variety of species you can put into the system, the wider the available spread of nutrients, and therefor the more healthy your system is. I am worried that my 50 gallon minnow tank may be too small relative to my 250+ gallon catfish tank, but I really can't do anything besides trial and error in that respect.

Dissolved Oxygen Levels
This is my current hang-up. I feel confident that I can supply adequate oxygenation for the fish via waterfall effect, circulation, and air pump aeration. I am not however confident that I will be able to maintain adequate DO levels for my grow given the typical bio-bucket grow. Bio-buckets rely on circulation and waterfall aeration to maintain DO levels rather than air bubbles in a recirculating DWC. This is a more efficient method, but it is limited by the length of the feed line and drain line. If I incorporate all flowering, vegging, and cloning/mother rooms, I will end up with a feed line and drain line run of about 30 some odd feet. This is far further than I have run bio-buckets in the past. I may end up having to add air stones to the bottom of my 5 gallon buckets, but this too is a situation where I will have to just wait and see. After growing all this time without airstones, I am loathe to begin. I will make every opportunity to provide for adequate aeration in the reservoir, so that I don't have to supplement in the buckets.

Well, this post is already far too long. If you would, please look over my plans and critique as needed. I am open to any and all suggestions.

Thanks
NTS