Aquarium DIY CO2 Generator System Kit, G200

Ok, this CO2 Generator System kit is intended for a citric acid setup. Guess what? It works for yeast too. One caveat with yeast vs. citric acid... If you let the pressure build up on yeast, the mixture's CO2 content will increase and the pH will drop. You can potentially shut down the fermentation through pH drop and CO2 toxicity, although the yeast will likely just go dormant vs. dying. What this means is that shutting off the white on/off valve to build up pressure is unlikely to produce enough pressure that your gauge will show anything at all. Even with this, you can build up enough pressure inside the generator bottle that you can use the regulator. I use a Paffrath bell to regulate the amount of CO2 in surface contact with my aquarium's water. This is probably a better idea than using a CO2 fine-mist diffuser for yeast, since you have less control over production volume and it's better to waste a little bit of CO2 than to overdose your tank. What I like: - Tight seals on both bottle caps and hose fittings. - I like the high-quality appearance. - No messing with silicone and adaptor fittings, this thing just goes together. - Use whatever size bottles make sense as long as they fit standard-sized caps. I use a 2 liter for the yeast generator and a 1 liter for the bubble counter. - No durability issues so far with any hose or fitting failures. - I can position the whole assembly behind my micro-tank without worrying about appearance.

I wanted to do the sugar and yeast method, so I just pulled out the parts that go in the bottle. I put in one cup of sugar, one teaspoon of brewer's yeast, and warm water. With this setup, I've never had a problem with leaking and the only time I got it in my tank was when the bottle was knocked over. I love that I can turn it off at night because I was worried about suffocating my fish. This was really easy to install and it has definitely boosted the growth of my plants. I recharge each bottle every 20ish days, on an alternating schedule, and all my plants are bushier. No pearling, but my drop checker reads green. I highly recommend this for anyone with a lower light setup who doesn't want to shell out for real CO2 power.

The cos 2 system works, but you run through citric acid and baking soda within a month

The kit works great only bad thing is the valve that comes with the system, if you let your pressures get above 1.5~ adjusting bubble rate becomes a real challenge. I have come home to dangerously high co2 levels 2 times because of the valve although I shouldn't have left the system generating co2 while I was gone so you could attribute that to user error. Great bang for your buck and my plants are thriving thanks to this kit.

The two-bottle CO2 reactors suck. They're prone to clogging the line with baking soda, the valves are of poor quality and hard to modulate just right, and always seem to release CO2 in massive surges no matter how I adjust the primary and needle valve; I've tried the ball valve wide open and the needle valve to regulate by itself, I've tried just cracking the ball valve to assist the needle valve with regulation, trying to target 4-8 bubbles per second for my 4x3x6 grow tent (my setup is bottle output -> solenoid -> ball valve -> needle valve -> hose to tent -> bubble meter -> diffuser in jar of water), and it is very inconsistent. I've tried purging all the lines with air, added a solenoid valve to run off a timer in tandem with my grow lights, so the valves can be set in place essentially calibrating the system so when I refill I don't touch the valves at all... all to no avail - sometimes the acid is consumed in a day or less, and sometimes it will last a week or more. The system just plain sucks - and yes, I've verified there are no gas leaks. The valves in this kit are just a really poor choice for this application. Great concept, but really lousy implementation. I'm taking this system and tossing it in favor of a stainless steel bottle reactor that uses a single bottle with a proper pressure regulator and high-quality needle valve. I suppose the best I can say about this is that this review can save you wasting money on an unreliable solution. :D

This kit requires nearly daily maintenance. Initially, I expected to refill the baking soda and citric acid only every other week. However, regular water replacement is also necessary. The water is transferred from one bottle to another via a slow but steady siphon process. With a 1L bottle (4 qt) filled halfway, one bottle empties after a day while the other fills up. Exercise caution when replacing the water. The bottles are highly pressurized, and there is no release valve. To safely open the bottles, you need to remove the diffuser and release the CO2 before unscrewing the caps. I once made the mistake of loosening the cap slightly to release the pressure, which caused the cap to pop off and water to splash out. The water, after reacting, becomes sticky like syrup, resulting in a considerable mess. Although the chemical product is low in acidity and food-safe, it still makes me anxious each time. Additionally, since the two bottles are attached, the entire setup is physically unstable. If the bottles fall, liquid can enter the gas outlet pipe, flow directly to the diffuser, and potentially reach the pressure gauge as well. This risk is particularly high when changing the water or refilling the reactants. The kit includes a magnet to stop the reaction by moving the pipe away from the reactants. However, this needs to be done twice a day, which can be inconvenient. Overall, the solution is not sustainable in the long term.

The system basically comes preassembled, so it's plug and play. I put sugar and yeast into Bottle A and RO water in Bottle B. You want the ball out of the sugar/yeast water for this method, so it doesn't foul Bottle B. Use the magnet for this. Anyways, it produces massive amounts of CO2 that you dial in with the needle valve and I was only using 1 liter bottles! The price is right for smaller tanks. I have a 20 gallon long.

I tried making my own setup and it wouldn’t hold pressure so I picked this up. I wish I knew about this product in the beginning because it works so awesome! I use it with yeast and sugar and get great results