Originally Posted by Ash
If I need to shut the Co2 injection off during the night are there any automated ways of doing so?
Before you worry too much about this, or work on systems to deal with it, you need to experiment with your mixture and your input method. Both can be adjusted to give a rate that is more stable and not excessive when used 24/7.
First, of course, be sure that you are not using a reactor that is just too big for the tank. No 5 gallon carboys for a 20 gallon tank, for example, and no 2 liter jugs for a 10 gallon even. IME, about 1 liter per gallon or less is OK. I used 2 liter jugs and 3 liter jugs on 20 gallon tanks, probably one gallon per 20 gallons is OK, depending on your mix.
In general, using less yeast will lower the initial rate. Also, if using bread yeast, baking soda can moderate the initial rate and prolong the total life of the run. Then you can try mixes using molasses or Jello which can have more moderate start rates and long life.
Then, do some measurements to see if you actually have a problem that needs fixing. It may be that the CO2 rate is not high enough to be an issue by morning.
Highly effecient input methods can be worked on. For example, if you use an internal power reactor you can power off for a few hours at night, or all night, and the gas will either build up or escape the reactor depending on design. Hard-plumbed filter run units, as in most external reactors, probably cannot be altered, but running an airstone can drive off CO2 at night.