I was 145 Lbs before I started smoking weed...
Join Date: Mar 2008
Location: Somewhere Out There
Starting A Medical Cabinet, Bubbler Principles, & Calculating Nutrient Levels
Just ran across this on another site and thought this would be a great help in getting a newb up and running. I wish that I had found a thread like this when I first decided to grow...
I am NOT the author, and I don't think that its perfect by any means; but it's a no-nonsense way of figuring out a basic setup, without getting ripped off at the hydro store like I did . They always want to sell you the "latest and greatest new thing" that will always kill your wallet.
Anyway, read and enjoy!
by Lucas of (what was) Cannabis World
Starting a Medical Cabinet and Bubbler Principles
Here is a "getting started in hydro" article I called the Double Quarter Pounder with Cheese, and one called "Bubbler Principles"
calculating supplies to start a med grow
this is just a draft, I invite all contributions
Lets say someone is interested in starting to grow their own Medicine. Here are some ideas on how to start picking out the components needed.
1. Pick a light WATTAGE based on quantity of medicine needed per month (conservatively estimate 3 months to yield 1 oz per 50 watts)
the following system elements all flow mathematically from the light size, buy nearest real world size approximations.
2. Calculate required exhaust CFM (Watts/4 is a proven ratio)
3. Calculate required GH Micro and Bloom nutrients, and pH down (if using tap water) to purchase. (Watts/400= quarts of Micro required for a 3 month crop cycle. Buy 2quarts of the Bloom for each 1 of the Micro, buy half as much pH down as Micro)
4. Calculate required plant numbers. (this is a very flexible number, Watts/100 is my personal preference.) I suggest you buy twice as many 3" netcups as you have plants.)
Notice items 1-4 are hydro store supplies, while there, you also need a pH meter, rooting hormone, some growrox for the netpots (dont be tempted by 4" rockwool cubes, they are not needed for a bubbler), and a water pump to drain the res,
items 5-8 can be had at wall mart or similar)
5. Calculate required reservoir GALLONS (Watts/25 is a proven ratio)
6. Calculate required airpump watts. (Watts/100 is a proven ratio)
7. Calculate required cloning fluoro wattage. (this is a very flexible number, Watts/20 is a good rule of thumb)
8. Calculate required square footage for canopy. (I love screens. Watts/50 is a good rule of thumb.)
Lets see how it works with an example. Jane Patient has Cancer, and a doctors recommendation to use Cannabis for pain, nausea, and appetite. She requires 2.5 ounces of High Quality Medicine a month.
1. 2.5oz x 50watts x 3 months = 375watts of light. The nearest real world size is 400watts.
2. 400watts /4 =100cfm exhaust blower
3. 400watts / 400 = 1 Quart of GH Micro, 2 Quarts of GH Bloom, 1 Pint pH Down if using tap water. For RO or bottled water, no pH Down is needed.
4. 400watts / 100 = 4 plants
5. 400watts / 25 = 16 gallon reservoir
6. 400watts / 100 = 4 watts of airpump power
7. 400watts / 25 = 20 watts of fluoros
8. 400watts / 50 = 8 square feet of canopy
putting the calculated results into real world equipment would look something like this. Jane would go to a hydro store and buy a
400watt HPS, a
95cfm Dayton Blower,
1 quart Micro, 2 quarts Bloom, 1pint pH down,
1 pH meter, REQUIRED! (no TDS meter needed with GH 0-8-16 nutes strategy)
8 3" netcups (twice as many as plant number),
1 stick of Fifteen 1.5" wrapped rockwool cubes (Four times as many as needed for 1 crop),
1 bottle of Clonex
1 small water pump and matching hose to drain bubbler
then she would go to Wall Mart or similar and buy a
15 gallon plastic tub, a
5 watt airpump, a
1 plastic airline
1 18watt fluoro fixture, (they are smaller than the 20watt and fit in a smaller tub)
1 nursery tray and dome, or cake and dome (eat the cake :-),
1 plastic tub to mount fluoro to lid as cloner
Janes biggest challenge will be to build a grow area that is lightproof yet has free flowing airways. It is best to intake from the house climate, and exhaust outdoors. If the ventilation needs are respected, temperature will not become a problem. Some of the materials I find valuable for lightproofing include Panda Plastic, and Foil faced insulation board. Im a big fan of 2x2 sheet metal corner brackets from Casa De Pot. You can assemble a very strong frame with 2x2" lumber.
I sincerely hope this thread serves to help new people.
Due to the large number of folks who claim they have found bubblers difficult and troublesome, I would like to try and address some of the reasons they dont love the initial experience. There are many ways to screw up a bubbler grow. Tops on the list is using too small a nute volume, which most folks in a bucket experience.
The problem with buckets, besides having to lift the lid off to change nutes, is that the amount of nutes is so small that evaporating a single gallon out of it, which can happen in one day under 250watts, will cause significant nute overconcentration. This will also create large pH swings. Also, with such a small volume of nutes, you will need to change out the whole mix very frequently, which many folks wont do because it is such a pain to lift the lid off the bucket. Then they will have pH problems, root rot problems, and plant health problems.
Another problem with buckets is the nute temperature can more easily rise too high, which also causes root rot. Another problem with buckets is light goes through them, causing algae growth, which can lead to nute and root problems. Another problem with buckets is you usually need more than one, which means lots of maintenance work.
Here is my humble contribution to what I think it takes to succeed in a bubbler grow:
First, use a tub that is large enough to delay the need for a change out of nutes to a 10-14 day interval. This will also mean your daily water loss will not be more than 10% of the total nute volume, which means your pH will remain in a safe range (5.3 to 6.3), and your tds will not go too high.
Next, use a nute strategy that involves topping only with water, instead of constantly mixing and adding fresh nutes for the topping solution. I suggest General Hydro nutes at 0grow-8micro-16bloom in milliliters per gallon as the mix for established, 12" tall clones with well developed root systems. For smaller plants and newly rooted clones I suggest 0-5-10.
If you use this system you MUST replace the entire nute mix once you have added an equal volume of water to the tub. So if you are adding 1 gallon per day to a 10 gallon tub, you replace everything after 10 days and start with a fresh batch of nutes.
To prevent algae growth, either use a non-transparent tub, or put a black garbage bag, or black plastic over it.
Here are my recommended nute volume guidelines.
For every 50watts of light, provide 2-3 gallons of res. So for a 250w light you want a 10-15 gallon tub.
For every 10 gallons of res, use 2-3 watts of airpump, and use a long stone, not a small one, and not a plastic one. So for a 250w light a 3watt airpump is sufficient. The only source of potential leak problems is if your airline comes off your airpump, and hangs below the water level outside the tub, so be sure it is well attached, use tape if necessary, or an antisiphon fitting. To keep the airpump quiet, hang it from a string, and the pump itself should be higher than the water line, again to eliminate the possibility of syphoning water out of the tub. One of the great things about bubblers is that a pump failure will not kill the plants, because the roots are always wet.
Use only one res per light, so you dont have multiple reservoirs to maintain. Use multiple plants per container, instead of separate containers per plant.
Use an aquarium water pump to drain your tub, so you dont have to lift the lid off the tub and move the plants. Tubs full of water get very heavy at 8 pounds per gallon.
I hope this helps new folks get off to a good start, and folks who have had problems to solve their problems. Bubblers can be very easy to maintain, and can produce very healthy plants. Also, bubblers are very easy to build, using wall mart parts, and do not take up as much height as ebb and flow systems, and do not have any plumbing that can leak.
Calculating Nutrient levels
I think it is possible to measure the EC of organic nutes. Once the composting of the organic source is complete, it produces water soluble nutes that the plant can use. Therefore, precomposted nutes, will produce water soluble extracts, like Pure Blend Pro, which can be measured on an EC/TDS meter.
I invite people who have facts about how much nutrient they use per gallon, to explore how much NPKand Mg they are supplying in their mixes.
The recipes I have been studying over the years have certain things in common, for example, the N levels usually run between 100ppm in bloom, up to 400ppm in veg.
The P levels generally run 40ppm in veg to 100ppm in bloom, but PBP recipes also limit P in bloom to 40ppm.
The K levels generally run 200+ppm in veg, and drop just below 200 for bloom, except Canna Coco recipes drop to 100
Mg levels tend to be in the 20-30ppm range for veg, and 45-70ppm for bloom
Here is the result of using The GrowGreen "Organic" Hydro Formula 15ml/gal PBPBloom, plus 5ml/gal Cal Mag
The Lucas Formula, thanks to pH, 8ml/gal Flora Micro, plus 16ml/gal Flora Bloom (or 8ml/gal FloraNova Bloom)
Notice how much lower the P and Mg levels are in PureBlend
I invite people interested in learning what their working nutrient recipe is delivering, to provide dosage info.
for example, if your mix is PBPBloom @15 ml/gal, plus 15ml/gal Sweet, instead of 5ml of Cal Mag, I volunteer to post the calculated results, if someone posts the guaranteed analysis of Sweet. I need the NPK and Mg percentages, plus the net weight of a 1 gallon bottle.