Reverse Osmosis Overview, Pros, Cons, Considerations, Your Wisdom

[snowkitty]

I am growing hydroponically in a bucket system and I’m not too happy with the lack of growth on my latest batch of clones. I am just starting to realize that nutrient lock-out might be a cause so I have been investigating reverse osmosis RO systems. Here is my summary of my situation and what it seems like ICMag users are saying about the pros/cons. Plz jump right in and tell me more and correct anything I’ve got wrong.

Snowkitty’s Situation
My tap water tests at 300 ppm. It leaves a white residue in my dog’s bowls so I suspect high calcium. From reading posts, it seems to me that people with levels over 100 ppm are the ones who pursue RO and report good results.

My grow consumes at least 100 gallons of water per week. I am using three 30-gallon reservoirs in three different rooms. Each room has its own faucet and I do my rez changes using a hose that is right next to each rez….so I have some thinking to do about how I want to get a centralized water source if I am going to install RO.

RO Pros

• Excessively high levels of minerals in your water causes nutrient lock out. High levels of calcium locks out magnesium & phosphorus. If you have high ppm in your tap water, your choices are (1) installing a RO system, (2) collecting rainwater, or (3) buying distilled water.
• You are going to get a more accurate ppm reading after you add your nutrients if you start with RO or distilled water that has a near-zero ppm to begin with.
• As you add RO water to your rez, the pH is going to remain stable overall instead of fluctuating based on the contents of your tap water.

RO Cons

• MJ plants consume high levels of Calcium and Magnesium so when you take it out of your tap water, it is going to have to be added back in your overall feeding plan. If you have decent tap water (without excessive levels of Ca, Mg, or others) than installing RO is overkill that you are going to have to compensate for later.
• RO water requires Ca/Mg micronutrients to be added back. You can do this by mixing tap water with your RO water (this solution is free but I am not sure how to dial in the right levels). Or you can purchase Cal Mag, Sensi Cal, Earth Juice, etc. Check your nutrient line to see if it is formulated to be used with RO/distilled water or not.
• RO systems generate an incredible amount of waste water. People have reported using 4 gallons of regular water to generate 1 gallon of RO water. Another statistic is that RO systems have a 5-15% recovery rate and the rest of your water goes down a drain.
• If you have a holding tank for your RO water, you can get bacterial growth. Someone reported brown algae if exposed to light.
• Faucet-mounted systems can be slow.
• For the purposes of gardening, we’re only concerned with the removal of excessive nutrient levels, and most RO systems focus on the removal of pathogens that aren’t an issue in gardening. So you might be paying for a lot more than you need when you could use a whole-house filter to target Ca/Mg hard water removal.

Important considerations:

1. What kind of water is your nutrient line formulated for? Does it expect RO/distilled water? For example…Lucas is formulated for RO…and GHFlora makes a hard water formulation. I don’t use either of those myself but it is a starting point to consider.
2. I wonder if soil vs. hydro growers care more about using RO water? I read that soil is more forgiving but I am very much a newbie and I have only done hydro. I’d be interested in hearing your thoughts on hydro vs. soil for RO.
3. In the Indoor Grows-Hydro forum, scegy mentioned just using a Britta filter for DWC and getting excellent results. I am very interested in this….maybe a faucet mounted Britta system could remove the heavy metals and chlorine that I care about??
4. Room temperature makes a difference in your output rate (not sure how high vs. low affects the rate…..)
5. FaderVader explained that there are two common household RO membranes: Thin Film Composite (TFC/TFM) and Cellulose Triacetate (CTA). TFC/TFM is non-chlorine tolerant (must use a carbon pre-treatment), less susceptible to fouling from bacteria, and rejects 98% of standard contaminants. CTA is chlorine tolerant, more susceptible to fouling from bacteria, and rejects 93% of standard contaminants.

Tell me your experience and wisdom!!
Do you use RO or have you specifically decided against it?
Do you have a storage tank or a faucet mounted system and why?
Tell me about how much RO water you produce in a day/week and how you manage it.
Do you add back micronutrients (Cal/Mag) when using RO water?
Name brand vs. the Ebay systems??

 

[One Love 731]

Here is a great article on the subject.http://www.urbangardenmagazine.com/index.php?id=190
Karma, One Love

 

[Aerohead]

RO is as good as it gets, gives you full control of the nutes and the misters, spray jets, ect don't get plugged as often. For me it's the only way to go but you bring up an interesting point. Don't know if I would still use RO if I had to supply 100 Gallons a week. That's alot of RO water and could be pricey to maintain that system. An alternative might be to try the GH hard water formula and get a large rubbermaid trash can to store water in before use, this way you would have better control of PH flux because you would be adding from a known stabilized water source. You could also throw some air stones in there and remove some of the solids using bubbles.

 

[Hella Fella]

RO is useless.......

the ONLY reason i would ever even think about it, is for aeroponics, and cloggin of sprayers [like an old showerhead with scale buildup]

Edit: Or if my only water was Creek\spring fed [not well water]

Its too expensive, its too time/water/filter consuming


Pro's & Con's all aside there are a MILLION different things effecting your plants with more impact with a few PPM's of tapwater


Calcium is GOOD for your plants, I buy Cal/Mag ADDITIVES @ like $60/gal, why would you want to REMOVE that?

RO is Allllllll marketing!



Just LOOK @ the length of your PRO vs. CON which is longer?




"Hard Water" is NOT that big of a deal, look elsewhere for improvments grasshopper!

 

[Hella Fella]

You could also throw some air stones in there and remove some of the solids using bubbles.

Good point!


Oxidation is POWERFUL, bubble a trashcan [NEW, clean!] full of water for 8-12 hours and PPM it then......

 

[MobbDeep]

i use the store side ro machine water..where i only pay 25c per gallon..is this water fine?does anyone else use it?im guessing its ro water,or deinozed water..and its fine for my grows..

 

[Aerohead]

I use the pet store RO water because I also have a reef tank. The store stuff is good just test it first because it depends on them changing out the membrane filters accordingly.

 

[FreezerBoy]

I'm running 0.5 EC (250-384 ppm) tap water with GH Flora Series without problems. Were I concerned, I'd try GH Flora Micro Hardwater formula. After that I'd try one of these ... DIY RO Filter

 

[mojogreenhand]

Ok...I have to say something. That DIY RO filter is NOT an RO filter. An RO filter by design utilizes a membrane and water pressure to force clean water through it. This DIY, in my opinion, is a complete waste of money. The DIY is most likely just a sediment filter filled with deionization media. This is the final stage in a RO/DI setup and is quickly depleted and rendered useless if high TDS water is run through it. This also brings me to a 2nd point. RO and RO/DI are different things. RO does not have a TDS of zero. I keep reading people on this site making this claim. Most RO systems will being water down to a TDS reading in the low teens, sometimes higher sometimes lower depending on source. The DI will then finish the job and bring TDS to zero. RO water is what most people will use for drinking water as it is not recommended to drink RO/DI since it is stripped of important minerals. RO/DI is used extensively in the reef aquarium hobby because that sort of reefer wants the cleanest possible water. Now as far as the DIY is concerned, please do yourself a favor and just save a few more dollars for an real RO system if your water is so bad that you'd need to try something like that.

 

[Zizu]

I have hard water(500ish ppm) and use GH hardwater and the lucasish formula. Works great. I had a hard time doing the addback with tap water as my numbers would go thru the roof so now I add back with RO from the store. Works like a charm.

 

[ogatec]

My tap water tests at 300 ppm. It leaves a white residue in my dog’s bowls so I suspect high calcium. From reading posts, it seems to me that people with levels over 100 ppm are the ones who pursue RO and report good results.??

sounds lije you could benfit from a good ro filter...

[/QUOTE]
My grow consumes at least 100 gallons of water per week. I am using three 30-gallon reservoirs in three different rooms. Each room has its own faucet and I do my rez changes using a hose that is right next to each rez….so I have so??[/QUOTE]

i would use a long line running off the ro filter, when u are done filling your storage tanks just roll it up...will work fine


[/QUOTE]RO Cons

• MJ plants consume high levels of Calcium and Magnesium so when you take it out of your tap water, it is going to have to be added back in your overall feeding plan. If you have decent tap water (without excessive levels of Ca, Mg, or others) than installing RO is overkill that you are going to have to compensate for later.[/QUOTE]
  
  not with a high quality fertilizer, most are calibrated for r/o so no additions will be needed, infact all that ph up or down used to chase ph in unfiltered water will prob do more lockout damage than missing cal/mag from filtered water.
  
  
  [/QUOTE]
• RO water requires Ca/Mg micronutrients to be added back. You can do this by mixing tap water with your RO water (this solution is free but I am not sure how to dial in the right levels). Or you can purchase Cal Mag, Sensi Cal, Earth Juice, etc. Check your nutrient line to see if it is formulated to be used with RO/distilled water or not.[/QUOTE]
  
  somewhat true, cal/mag is cheap & easy to use, not really a neg...
  
  
  [/QUOTE]
• RO systems generate an incredible amount of waste water. People have reported using 4 gallons of regular water to generate 1 gallon of RO water. Another statistic is that RO systems have a 5-15% recovery rate and the rest of your water goes down a drain.[/QUOTE]
  
  ya if you are using it allot. it does waste water but its not really that noticable, i bet you waste more flushing the toilet every day.
  
  
  [/QUOTE]
• RO systems are complicated, require intake and a drain, require filter replacement, and require some active management.[/QUOTE]
  
  ro systems are more complicated than not using one, but they are VERY simple & easy to use. filter replacment & active management are over rated..ive had mine for over 3 yrs now with no leaks or changed filters..still works good as new.
  
  
  [/QUOTE]
• If you have a holding tank for your RO water, you can get bacterial growth. Someone reported brown algae if exposed to light.[/QUOTE]
  
  if you are worried about bad bacteria put an airstone in yer tank, but i dont have any problems without. (i wouldnt drink that water tho)
  
  [/QUOTE][*]Faucet-mounted systems can be slow.[/QUOTE]
  
  yes! but thats why we have storage tanks..
  
  [/QUOTE][*]For the purposes of gardening, we’re only concerned with the removal of excessive nutrient levels, and most RO systems focus on the removal of pathogens that aren’t an issue in gardening. So you might be paying for a lot more than you need when you could use a whole-house filter to target Ca/Mg hard water removal.[/QUOTE]
  
  overkill? mabey, but they are cheap,simple to use, and they work great for people with bad/hard water.
  
  
  
  Tell me your experience and wisdom!!
  Do you use RO or have you specifically decided against it?
  
  yes been using 1 for prob 5-6 years now, tap water 350-360 w/o i grew w/o a filter for 4-5 years with great success, but i had to use LOADS of ph down and my ph would swing wildly. i have paid for my unit in not having to use so much ph products since then...
  
  [/QUOTE]Do you have a storage tank or a faucet mounted system and why?[/QUOTE]
  
  faucet mount with a storage tank. these systems are slow, thas there only real con..
  i have been using a 35 gallon trash can for a storage tank & it works great. i am about to upgrade to a 100 gallon tank because my system is getting bigger.
  
  [/QUOTE]Tell me about how much RO water you produce in a day/week and how you manage it.[/QUOTE]
  
  depends if i am changing out rezez or not.. on average i use 100gal a week or so. i use a timer so i dont overflow the trashcan 4hrs for 35 gallons not too bad.
  
  [/QUOTE]Do you add back micronutrients (Cal/Mag) when using RO water?[/QUOTE]
  somtimes, calmag is cheap & good
  
  [/QUOTE]Name brand vs. the Ebay systems??[/QUOTE]
  
  glad u asked...my ebay 1 leaked and looked like it was put together by some dude in his garage($90). I prob could have taken it apart & fixed it if i was mechanically inclined but decited to get the hydrologic 200gpd ($250) and its been ROCK solid for the last 2-3 yrs...
  
  
  
  IN MY OPINION,a ro filter seperates the serious/professional grower from the guy who is just doing it for fun. if you are serious about growing more than a couple of cycles ,then its a worthwhile investment. Unless you are a lucky bastard like my brother whose tap water reads less than 50ppm!!

 

[One Love 731]

The DIY RO filter, although may not be an exact RO filter, does take tap water from 380+, all the way down to 15ppm. At a price of around 15-25 dollars. If you don't think that's worth the money, read the link in post #2. Karma, One Love

 

[mojogreenhand]

Opinions are like butt holes, we all have one and most stink. The DIY RO filter, although may not be an exact RO filter, does take tap water from 380+, all the way down to 15ppm. At a price of around 15-25 dollars. If you don't think that's worth the money, read the link in post #2. The last thing I want to do is offend anybody. Fact is more important than opinion. Karma, One Love

First off to call it an RO filter at all is completely inaccurate. Go ahead and call it just a filter but to confuse people with labeling it a RO filter is wrong and misleading.

Secondly, at the price of 15-25 dollars I definitely do not think it's a good idea. For that price if you do 4 or 5 times you've already paid for a real RO filter.

Thirdly the different experiences people can have with your DIY filter due to the differences in source water is bound to frustrate people and from reading that thread it shows that for some people it depletes quicker. With a true RO filter you will get even results as long as it's set up correctly from almost all drinkable water sources.

Finally, the amount of money people save by growing their own and the amount spent on nutrients and additives to give you the best possible results don't you think it's worth it to start with good water to begin with. To cheap out on a filter seems seems silly.

But again this is just my stinky opinion...

 

[One Love 731]

mojogreenhand I love your screen name. I tried to PM you but it did not work, when you get to 50 posts that will be a possibility. The last thing I wanted to do was to sound like an authority on the subject, as I am not. I am new to a lot of this, I get almost all of my knowledge form reading and if I pass it on I never represent it as my own.The title may be misleading but if you take the time to read on you realize this is not represented as an RO filter. I personally can not afford the RO filter I want right now so rather than packing store bought water in, A 15-25 dollar filter is a temporary fix. As I hope you would agree, its better than nothing. I to believe RO is worth its wait in gold, I am just a little short on gold rite now. After a few pay checks I want to get a good RO filter that would work to maintain ten 40 gallon rez's. Do you have any recommendations for a good unit, at a fair price?
Karma, One Love

 

[snowkitty]

So...I am no longer debating any sort of "do I need RO" question. While I was researching the topic, it was time to change for a rez change, and we went out and trucked in distilled water from the supermarket. Kind of pricey but the proof is in the results...managing ppm is soooo much easier and the plants are sooooo much happier.

I am definitely purchasing an RO system and now I am wondering if want a system in the 100/200 gallons per day (200 gpd) range or the 700 gpd range. The only two that I've found in the 700-750 gpd range are the Hydrologic Merlin Garden Pro ($550) and the GE Merlin ($350). Most of the reef systems, ebay systems, thefilterguys.biz, etc. are in the 50-150 gpd range, which I think might be frustrating given the amount of water I need each week. I discovered that my 30 gallon reservoirs actually need much more than 30 gallons when the water flows through my entire system. Yeah, I figured that one out when I was trucking all that water on...LOL...

 

[snowkitty]

I think it is great is someone made a DIY filter that reduces their ppm...if it makes you happy to rig something up for a few bucks and get ppm reduction then I think that is awesome.

I really don't like that the DIY filter has the word "RO" in the title. That makes it confusing when people like me are doing research on RO...it's really just a filter, a DIY filter that someone got really good results with...and it should be called that.

I think it is great that people are expanding the hobby and posting their results with innovative filters...just don't misrepresent the science side of it...

 

[mojogreenhand]

Whoa...you do not need a 700gpd system. Take a this system for example. It's an 85gpd system. Other than the initial fill of the reservoir how much water are you adding to it on a daily basis? I'd imagine not more than 3-4 gallons. I rarely add more than 2 gallons. The system linked has a storage tank that holds about 3 gallons or a bit more so you have that much on hand at any given time. If you need more than that at any given time then you fill a storage container before hand (I use rubbermaid brute trash can). I use a 75gpd system and it's plenty and has a large reef system to support as well.

 

[snowkitty]

My original estimate on water usage was wrong...I am only running one room right now but my usage will be 150-200 gallons/week easily when I have all three going. I definitely do not think anything under 100 gpd will suffice when you need as much water as I do. I'm not that patient...

 

[drdee]

Hi Snowkitty,
My grows improved when I added an RO filter. I was at 335ppm and an inexpensive 85gal unit lowers it to around 30.

I use a 35 gal ag tank as a storage unit with a demand pump for delivery. Without that, you'll have to have some temporary storage since the RO water comes out quite slowly. You only get the rated output if you have water pressure according to what their specs require. Otherwise, you'll produce less. If I empty my 35 gal tank, it will be full the next day. Removing all the calcium really lowers your water ph. Mine went from almost 8 to ph6.
Good luck,
Dee

 

[One Love 731]

"Quote" OK, so before the flames start to roar, I admit it. It’s not a true R.O. unit. However, if you are taking the time to check out this post, then it might be just right for you. So here’s the story…"

OK, nobody took the time to read the first paragraph in the link that has been debated. I think its a great title, that's how I found it. Its a key word, as used on google when your looking for something exact, or something with the same use. Lowering your ppm is a huge part of why growers use RO filters. I have nothing but love for everybody on ICmag. Lets try and get back to RO.
Karma, One Love