CO2 Pads "Green Pads" explained - DIY Project NOT with smelly yeast.

I just wanted to share a bit of research I did on the topic. The content in the pad has to be food safe to use. This means you have to be able to consume it. CO2 can be produced using sodium bicarbonate and citric acid. If you use powdered citric acid and baking soda with some moisture you can produce CO2. These "Green Pads" are just meat packing pads. Once they get wet they start the reaction and CO2 is produced. CO2 is the only gas in the atmosphere that can prevent decay. So these pads are used to increase the shelf life of meat. So it turns out that many industries use this same material, floral companies, plant shippers, fish and poultry, the list goes on. Based on how much moister the pad receives will "regulate" the CO2 production.

As an experiment, take some white vinegar (contains 5% citric acid) and some baking soda, mix them to together is a glass. It'll bubble like crazy. The bubbles contain CO2. If you put this same mixture in a bottle and put the cap on... It'll explode.

I saw these in the grow shop and bought them to try and produce CO2 without buying an expensive setup. When I opened the ziplock I thought.. "Hmmm, this looks like one of those meat package pads." So I googled the meat packing pads and found the company who makes them. Then I looked up where to buy them and I found a site that sells them 2000 for $50; for the small 4" X 6" pads. The grow shop sells 10 for $14. It takes about 7-10 to get through a propagation, or so it seems. Some have claimed that in 4-5 days they had roots everywhere. The grow shop I go to showed me some tomato plants that were ready for soil in 4 days. They really work in the propagation dome.

10 grams of citric acid to 14 grams of sodium bicarbonate will produce roughly 1 gallon of CO2 gas. You can buy a whole box baking soda (1lb) for ~$1.50. You can buy 5lbs of citric acid for $16.

There are 7.5 gallons in one cubic foot. Based on some rough math it would take ~8 teaspoons per cubic foot to achieve 1500 PPM of CO2. Since most everyone uses fans in the flower room you would have to calculate your requirement based on the cubic foot of your room. CO2 is heavier than oxygen. My tent in 3 X 5 X 6.5. It will take 808 teaspoons to reach 1500 PPM. 1 gallon is 768 teaspoons. So, roughly 1 gallon will fill my room. Looking back to the calculation you'll notice you can make a hell of a lot of CO2 for ~$20.

As moisture is added to the solution the more CO2 will be generated. This is why these pads require a mist spray or high relative humidity to produce CO2.

I am sure this same company that sells 2000 for $50 has the large size pads too. I'm going to find a way to manage the reaction so I can regulate the amount of CO2 is produced using the citric acid and sodium bicarbonate process.

Just thought I'd share what I was working on.

i just saw something about those pads today. thats interesting i didnt know that theyre the same as those meat pads. what website u find those pads on?

cool, keep us posted on your progress.

I found a way to make sheets for the clone dome pretty easy so I'm posting those directions soon. I want to do a video. I'm very challenged to find a way to reliably produce enough, without creating too much pressure, for a tent. I'm not giving up though.

the green pads are another example of something simple, costing thousands of % more due to it's now in a hydro shop. They are exactly the same as the meat pads, just a bit bigger.

So if you want a similiar size buy the florist ones instead(same people as the meat pads), they are twice, sometimes 3 times as big. I've only had a sample, but i like the cooling effect they also give, they will be very beneficial to me on the warm stuffy days.

anybody have a link to meat pads

Look here - http://www.ebay.com/itm/DIY-planted-aquarium-CO2-kit-system-diffuser-tubing-/250830168813


[video=youtube;9yp0MJfVJsk]http://www.youtube.com/watch?v=9yp0MJfVJsk[/video]

Pretty simple to get the siphon to drip vinegar/acid into your baking soda. There's a video somewhere showing how that kit works - pretty cool system to finely regulate how much CO2 is being produced. Might also find this site helpful: http://www.hydrofarm.com/articles/co2_enrichment.php

what happened to the link to the meat packing pads??? would love to check it out.

http://www.jsfoodbrokers.com/co2-pads.html Lots of info

interesting......thanks.

Anyone try these things out yet? I am curious, and would like to try them in my small 8 sqft tent. Anyone?

I'm wondering about the possibility of using an IV bag with a drip regulator to control the generation of CO2. With that one could precisely control how much acid is hitting the sodium bicarbonate.

CO2 Generation - another effective cheap crude method that could be refined by drip action

CaCO[SUB]3(s)[/SUB] + 2 HCl[SUB](aq)[/SUB] → CaCl[SUB]2(aq)[/SUB] + CO[SUB]2(g)[/SUB] + H[SUB]2[/SUB]O[SUB](l)
[/SUB]
in other words,

Calcium Carbonate solid + Hydrocholoric Acid liquid = Calcium chloride + Carbon Dioxide gas + water

Where do you get Hydrochloric Acid? Lowes in the solvents section of the paint department ($8-9 for plenty). Often it is call Muaratic Acid and packaged in a plastic bottle. As with any acids, care must be given as it will burn you and ruin clothes, but with simple and careful planning / handling, hydrochloric acid should be easy enough to work with. Common sense and slow deliberate actions.

Where do you get calcium carbonate? many places including Lowes. Naturally, many things are made from it to include sea shells, coral, egg shells, snail shells. An easier source is from Limestone or better yet, marble (limestone that has been extremely heated and pressurized inside the earth). You can buy 40 lbs bags of quarter size rocks at Lowes in the garden area for < $5.

How can you use it? Simple put the marble rocks in a plastic container, add some water, pour in the hydrochloric acid. You get 8-12 hours of carbon dioxide production.

A simple set up would be: attach some hose to the bottle top of a wide mouth bottle (like a 3 liter) and run the hose to your plants (or fan for dispersion). Drop 5-6 decent rocks in there, fill the container 1/4 full of water, pour in an once or 2 of acid and put the bottle top/hose back on. Depending on your aeration in your grow room, you may either add more acid or more lime stone as necessary.

Caveats:
1. stuff a bit of polyester cloth in the tube near the bottle cap so residue / fizz mist cant go into and travel through your tube.
2. I tried limestone I picked up from nature and it contains other things like clay and other minerals that eventually form a mud layer over the rocks thus not allowing the acid to effectively make contact or the contaminant itself would bond with the acid and inhibit CO2 formation. Marble works the best.
3. You can use baking soda instead of marble. Many people use vinegar and baking soda, but vinegar is a 'weak acid' while hydrochloric acid is a 'strong acid'. Hydrochloric acid gives you much more bang for your $/buck. Much more.
4. Once the reaction stops the mixture will have either more marble left or more hydrochloric acid left to react with. It is safer to 'top off' by adding marble rocks and a little water than to just add more acid. i always ensure the mixture's acid is depleted before I add more acid. See #5 for why.
5a. you can continue to add rocks and acid to the container till the mixture is saturated with contaminant and calcium chloride. I then add a cup of water and some more marble to make sure there is no more acid to react with. I dispose of the mixture by pouring it onto on to a pile of lime normally used to adjust ph of soil or lawns (or onto a tree stump I am wanting to ensure is dead). Though the mixture is 'toxic' as is, it will neutralize and break down. It is unlike many pollutants that won't and remain persistent. It will effect ph of surrounding soil for some time.

5b. I recently used a bottle of 'low odor' hydrochloric acid and it seemed to not work as well with marble but did just fine with baking soda. A better explanation is that after the first 5-6 rocks in that container, I added more rocks (to see if any acid was left to react with) and saw very little action - it only partially dissolved the marble by the next day. When I put a spoonful of baking soda in that same rock/acid mixture, the baking soda reacted and it took 4-5 spoonfulls to deplete the remaining hydrochloric acid in the mixture. I poured that all out and tried again with with a new solution of 5-6 rocks - normal reaction for several hours. I put more rocks in the next day and little reaction. I squirted in some off-the-shelf hydrogen peroxide (H2O2) and the reaction started taking place again with the newer rocks and remnants of the old rocks. It seems the 'low odor' kind gets saturated very easily and the weak peroxide basically diluted the saturated solution to below saturation point. The peroxide easily would break down in the mixture and provide even more. I can also assume some o2 (oxygen) was also made.

Though this CO2 method sounds rough and crude, it is not hard to do and could be easily refined and made more precise. I don't see the need since my air is exhausted and I know I am loosing CO2 with the exhaust. I don't have the want nor the funds to measure CO2 levels. For me, just raising the CO2 in the less accurate way I do has dramatically improved growth. Good enough for me right now.

some thing else about CO2: It is heavier than oxygen and it lowers pH of liquids. It sinks to the bottom of the grow room so you must have decent circulation to make the best use of it. My air pumps were on the grow room floor and therefor picking up and pushing CO2 into the hydroponic nutrient solution. My pH started to drop when I started making CO2. I moved the air pumps and the pH drop problem went away.

This may not be the clearest post, but the basics should be easy and a method to make CO2 like this can be refined very easily.

Where to get a metered dripper?