The Puffer Forum

I have been researching the whole DIY CO2 thing before I go ahead a do it I began researching the fermentation process and exactly what it involves. First of all my setup will involve 2 1 liter desani bottles and a dorm fridge sized soda bottle. the yeast solution will be in the desani bottles with two hoses going to a T connector and a hose going to the soda bottle and a hose from the soda bottle to the aquarium. I plan on using a airstone in the aquarium to diffuse the co2 in the water.

Now for my actual question. I read that the production of alcohol can be curbed by oxidizing the solution (or introducing oxygen to the mixture some where). I began thinking the ways in which this can be accomplished for the DIY co2 application. Here is my hypothesis, could the introduction of an airstone to each bottle connected to an air pump be enough to oxygenate the mixture and stop the production of the alcohol. now if this were to be done I do understand that there would be some extra pressure in each of the bottle and assuming that the bottles wont explode then there would just be a increase in co2 flow rate to the aquarium. so for some main points

1. would this actually stop the production of alcohol.

2.would the pressure be too much for the bottles.

3. would the mixture of co2 and oxygen in to aquarium through the hose at the same time hurt or help.

4. how long would the yeast actually survive assuming that you replenished the food (sugar). or if you didnt.

any added suggestions or thought would really help. (dont bash me if this is on the forum already)

DIY CO2 isn't that difficult but you will need special hoses. Regular airline tubing won't do it. You can get little flow valves that attach to the CO2 lines. AFAIK you can't produce CO2 without producing alcohol. The alcohol can be rendered useless by adding O2 at the end. Not sure how it would work during the actual production.

DIY CO2 is production en mass is very unpredictable. CO2 isn't produced in a steady stream.. it starts slow, then goes strong for a while and tapers off.

Having the extra bottles to store the CO2 in is good in case of a pressure buildup.

I know LilSwimz had a small DIY Co2 set up. I went pressurized because the mixing and Production can be a PITA.

What's the point of limited alcohol? Unless you get it siphoning and it floods, its not gonna mix. Just get a check valve and your good. For tubing silicone tubing is best, the blue kind, it doesn't corrode nearly as fast as regular clear tubing does.

I use about 3/5 gallons to 2 cups sugar and 1/2 tsp yeast for 30 gallon tank.
I change the whole container every two weeks. Make sure you get some sort of drop checker up, or you run the risk of gassing your fish/puff/shrimp.

The primary issue with DIY CO2 production is exactly as J_P detailed in his post - the production is unstable.. It starts slowly, peaks, and then fades. This is not very good supplementation. The best work-around for that IME is to use multiple bottles, 2-3 per tank. One bottle can be freshly set while the 2nd is peaking and the third fading. These are replenished in sequence and production is steadier but not fully stable. Two bottles will help if one is reset while the other is at peak production.

The most stable production will be with the fermentor bottles in a heated water bath for constant temperature unless your room is absolutely evenly heated and cooled. The production bottles should be individually valved such that any one can be removed for refreshing without wasting gas.

A trap bottle as you describe I do consider absolutely essential. The input tube from the production bottles should go down near the bottom of the bottle, the outlet line should take in gas near the top of the trap bottle to avoid passing any fermentor juice to the tanks.

The use of any check valve in the system is asking for an explosion in the system - such can do serious damage - any absorbent material hit with the spray needs replacing - that does include drywall and wood floors as well as rugs, mattresses, many fabrics, and all books. It is not worth the risk. I would rather mess up a tank than a room.- it is cheaper.

Baking soda may be added to the mixture to help stabilize production a bit.

If airstones are used, they should be traded off and cleaned routinely or replaced. A clogged airstone is dangerous. Any airstone increases the internal pressures throughoutt the system.

Finally and frankly, I get much better results with Seachem's Excel for moderately lighted tanks than even with multi-bottled DIY gas fermentor systems. I don't think it is even as expensive as is the DIY setup, but I do get mine in large bottles.

A high-light system is likely to need pressurized gas.

HTH

The point that i was tryna make is that if you can limit the production of alcohol by introducing the oxygen, which will limit its production. I know this because that is how they make wine with lower alcohol contents. but if you limit alcohol the yeast will live longer. I they live longer then you have a longer period of co2 production ( as long as you continue to feed the yeast.

Limiting CO2 production in the case of DIY is more likely to reduce the effective CO2 concentration in the tank. The biggest issues with DIY fermentation is not the lifespan of the culture, but the tank level of CO2 and its stability. In other than the smallest tanks,it is not easy to get effective levels and hold them over time.

Here's a drawing of the DIY CO2 I use. It works very well.