I'll chime in here and show what I did to supply CO2 to my tank. My tank is 10 gallons. I have a 25 in the garage, but wanted to keep things small until my two kids (6 and 3) get older and I have more time.
My system consists of a citric acid-sodium bicarbonate generator. I have a connector on the top which contains a gauge, bubble counter, check valve, and relief valve. My unit cost me $50 US (I know other set ups may be cheaper). I got 2 kg of baking soda from Walmart for $5, and 3 kg of citric acid from my local soap shop for $15. Total is $70.
I didn't have a clue how this worked, but it does! What happens is that when you squirt the acid side (A) into the NaHCO3 side (B), bubbles will form. B will then pressurize then send CO2 through the line and bubble up in A. The rise in pressure in A will register in the overlying pressure gauge. As CO2 is depleted from the needle valve located at bottle B, the pressure will drop relative to the A bottle. This pressure differential will then cause the citric acid to re enter the line. Given enough time, the citric acid will finally drop into B, restarting the reaction and the whole process starts all over again.
It's not like the acid in A rushes over to B. It's a very slow process and appears to be self regulating. The only thing you have to do is swirl the liquids to ensure the reaction is complete, when it happens.
The instructions say to continue the reaction until the gauge reads 2-3 kg/cm2.
I prefer to leave it at 1.6 kg/cm2 as the needle valve is less fiddly at the lower pressure than the higher pressure. Plus I feel more at ease when the system is at a lower pressure overall. 1.5 kg/cm2 is enough to send many many bubbles/s through my single ceramic diffuser. I find the flow easier to adjust at this lower pressure.
My only complaint is that the seals in the bottle connectors are not really that great as I got leaks. I replaced them with ordinary garden hose seals and had no further problems.
I've had my unit going on for the last 7 days (on 12 hours, off 12 hours). Given the rate of citric acid depletion, I would estimate 1 - 2 months until I have to dismantle and replenish the system. The pressure really is stable and does not fluctuate. I'd say I have enough NaHCO3 and citric acid to last me at least 1.5-2 years!!!!
Yes there are rubber seals, and they probably do deteriorate given time. I fully expect to replace all rubber seals when the unit needs to be replenished. I think this is a small price to pay for the upkeep of the system. Plus the rubber seals should only cost a few dollars at most at your local Home Depot or other hardware store.
The system is enabling my tank to stay steady at pH 7.0 at a KH of 6dH.
Here's my set up:
CO2 Diffuser
Generator as it appears under my desk.
Not a big fan of the surf shop, but guess the kids need their fun! Could be worse...
My tank was planted two weeks ago. Hopefully within a month or two the foreground plants will have formed a nice carpet. The background plants should also grow out and become more dense. The fake plant on the middle fixture is a bit of an eyesore, as is the surf shop. I'll probably cut that fake plant and tie on some java fern or something.
Enjoy!
My system consists of a citric acid-sodium bicarbonate generator. I have a connector on the top which contains a gauge, bubble counter, check valve, and relief valve. My unit cost me $50 US (I know other set ups may be cheaper). I got 2 kg of baking soda from Walmart for $5, and 3 kg of citric acid from my local soap shop for $15. Total is $70.
I didn't have a clue how this worked, but it does! What happens is that when you squirt the acid side (A) into the NaHCO3 side (B), bubbles will form. B will then pressurize then send CO2 through the line and bubble up in A. The rise in pressure in A will register in the overlying pressure gauge. As CO2 is depleted from the needle valve located at bottle B, the pressure will drop relative to the A bottle. This pressure differential will then cause the citric acid to re enter the line. Given enough time, the citric acid will finally drop into B, restarting the reaction and the whole process starts all over again.
It's not like the acid in A rushes over to B. It's a very slow process and appears to be self regulating. The only thing you have to do is swirl the liquids to ensure the reaction is complete, when it happens.
The instructions say to continue the reaction until the gauge reads 2-3 kg/cm2.
I prefer to leave it at 1.6 kg/cm2 as the needle valve is less fiddly at the lower pressure than the higher pressure. Plus I feel more at ease when the system is at a lower pressure overall. 1.5 kg/cm2 is enough to send many many bubbles/s through my single ceramic diffuser. I find the flow easier to adjust at this lower pressure.
My only complaint is that the seals in the bottle connectors are not really that great as I got leaks. I replaced them with ordinary garden hose seals and had no further problems.
I've had my unit going on for the last 7 days (on 12 hours, off 12 hours). Given the rate of citric acid depletion, I would estimate 1 - 2 months until I have to dismantle and replenish the system. The pressure really is stable and does not fluctuate. I'd say I have enough NaHCO3 and citric acid to last me at least 1.5-2 years!!!!
Yes there are rubber seals, and they probably do deteriorate given time. I fully expect to replace all rubber seals when the unit needs to be replenished. I think this is a small price to pay for the upkeep of the system. Plus the rubber seals should only cost a few dollars at most at your local Home Depot or other hardware store.
The system is enabling my tank to stay steady at pH 7.0 at a KH of 6dH.
Here's my set up:
CO2 Diffuser
Generator as it appears under my desk.
Not a big fan of the surf shop, but guess the kids need their fun! Could be worse...
My tank was planted two weeks ago. Hopefully within a month or two the foreground plants will have formed a nice carpet. The background plants should also grow out and become more dense. The fake plant on the middle fixture is a bit of an eyesore, as is the surf shop. I'll probably cut that fake plant and tie on some java fern or something.
Enjoy!
