When you do a DIY CO2 injection how long do you get CO2?

[jasno999]

I have used the method of adding yeast to sugar water in a bottle and then ducted airline into the tank so that the CO2 produced would bubble into the tank.

I like th emethod but was wondering how long you guys got out of the CO2 production for this type of method. I only got 2-3 days out of it at max. I am wondering if that is normal or if I am using the wrong mix of yeast, water and sugar.

 

[LunchBox]

I get about 2 weeks using 1/2 teaspoon of bread yeast, 2 cups of sugar, and a 2 liter bottle filled to the top of the label with hot water.

 

[Squawkbert]

Water too hot = dead yeast.

I use a 1L bottle, pretty full w/ RO water at room temp, ~3/4C sugar, 1/4-1/3 yeast packet (Fleischmann's) and I get 14-16 days.

I've seen where adding a little baking soda (or was it powder) helps - I guess it keeps the pH from going too far off. My guess is that having more water is the key to keeping the yeast from poisoning itself w/ ethanol. Once that's under control, it's a function of how much sugar you put in. I'm contemplating trying alternatives to sugar (starch/sugar mix or potato slices).

 

[Mikael]

I get about 2 weeks using 1/2 teaspoon of bread yeast, 2 cups of sugar, and a 2 liter bottle filled to the top of the label with hot water.

I use the same set up except I use room temperature water. I always also wash the bottle before using it with chlorinated tap water (to possibly kill off unwanted bacteria).

Mine is still producing CO2 after 4 weeks.

I think that a poor result is often due to several factors such as leakage, injecting the CO2 too deep (thus fighting water pressure) etc.

Use good quality bottles, like Coca Cola's and make sure that the drill diameter is considerably smaller than the diameter of the tubing. There is no need for glue. With my DIY reactor I get about 30ppm in the afternoon from 3 x 2 litres bottles in a 23g tank (takes two cups of sugar per week to maintain this). Took a while for me to realise that I needed a pump with at least 700l/h capacity, i.e., strong enough to prevent buildup of air at the top of the reactor.