DIY CO2, The Madhatter System

[essabee]

After coming out of the wild (read 'Meet Me' in the Intro Board) what intrigued me most about the hobby was the use of the major plant nutrient - CO2. As all my tanks were planted and in the high light section (that is a different story and will be dealt separately); I wanted to try out CO2 without investing too much so that I could remain non-committed. So it was DIY CO2 for me.

The way the DIY CO2 is used by a hobbyist is wasteful, the light off production, which naturally is half if not more, is allowed to escape into the atmosphere. I wanted a system where I could use it in my aquarium and not only that I wanted a system which could be capable to supply my favorite aquarium (6' X 3' X 2') and a few more.

Having learnt hooch making from the forest tribes, yeasts and fermentation were no strangers to me, but handling the bye-product - CO2 - was. I needed a system which would supply me with copious amount of CO2 without much flexibility/variation in the supply level.

Steady supply meant I must use small amounts (that is a comparative word) of yeast and a staggered CO2 generator bank. 3 generators with weekly recharging of one seemed a reasonable routine. Next was the volume of mix needed - here I was treading into unknown territory. All my queries had elicited that it was unreasonable to use DIY CO2 for large tanks. Then I am as hard to discourage as getting a dog to let go the end of a rope; so I decided to err on the larger than requirement size - 35 liter plastic jerry cans were my choice, 3 of them, 105 liters of yeast mix total. Being flat they would balloon under pressure so I needed to strap them together with strong belts. Nylon straps seemed appropriate and strapping them together seemed most practical as that would limit their flat sides from ballooning. It naturally followed that as I could not easily remove one can for washing and recharging, I had to use the siphon for discharging and a hose for washing. That meant each generator can need must have its individual stopcock to disengage it from the CO2 delivery system while the process of recharging was in progress.

DIY CO2 generation being a yeast action, it is temperature dependant. A steady temperature above 25° C would be necessary. So I decided to house all the generators in a tank built for them, submerged them, and use an aquarium heater to keep the temperature steady at 30°C.

To store the CO2 produced during lights off time; I put an empty 35 L. jerry can (as gas storage) in parallel to the supply line and a master stopcock after the connection and this can cut off the supply of CO2 to all the aquariums which are being supplied. At light off time I stop the supply and the pressure of CO2 builds up, the gas storage can balloons. This storage can lies on its side and although there are no straps on it to stop the can from ballooning, I have balanced a pile of bricks on it upper side and the weight of these bricks keeps the CO2 pressure steady (only a slight reduction) during the day.

ps Its been working for nearly 2 years now.

[Shadow]

I would say very impressive DIY CO2 but honestly it might be cheaper to buy pressurize CO2 setup. Especially in Singapore where area is limited. Those water container does not come cheap either. Not to mention the trouble for weekly recharging.

[bossteck]

6 x 3 x 2 tank is huge. For a tank that size, I would probably be feeding co2 24/7 rather than just during the lights on period.

[CK Yeo]

I wonder how many kilograms of sugar do you use and is it cost effective for an aquarium of this size?

ck

[essabee]

All the above remarks are completely valid if I had not used "used goods" (recycled goods) for making the system and hitched a piggy ride on the back of a moonshiner for supply of yeast mix and had a large terrace where I had ample space.

I started this project to gain first hand knowledge of the effects of CO2 in planted aquarium without investing in the costly pressurised CO2 equipment.

9 Kgs. of sugar, and 1 liter of molasses every week does not come cheap even when you are supplying CO2 to 5 large tanks. Then this was required for the learning process.

You all will be happy to know that I have with me (still to be set up) a 9Kgs. CO2 filled cylinder, the regulator with a solenoid valve, timer devices, half a dozen needle valves, and at present am waiting for the 200' of CO2 pipe and the splitters that I have ordered.

[CK Yeo]

At that rate, you can justify a 5L CO2 system in half a year (if you are in Singapore). Nevertheless, I agree that it is a good way to convince yourself on the benefits of CO2 in a planted tank.

ck