Check valve required?!

[Logy]

I'm building a DIY Co2 system for my 20 gallon tall. Is a check valve necessary? I've been to the local hardware store. I asked to be directed to check valves. All of the valves there were really big. Nothing close to the size of my tubing. Is it completely necessary or is it just a safety?

 

[Bk718]

a lfs carries check valves for $1-3
and its not necessary if you keep the bottle at level with the tank

 

[rich311k]

A simple plastic one should be cheap and small. I think it is a necessary fail safe. You don't want that goo in your tank.

 

[J double R]

not required, but highly desired.. and, well, a mistake you won't make twice in not having one.

 

[Squawkbert]

Personally, I don't use them despite keeping my jugs under my tank.

Reasons:
1) I use a pretty thin walled tubing, so capillary action is minimized to the point I can uncork both jugs, go and refill them and I get no water siphoning out. This may well be a result of using a good diffuser at the output end of my tubing combined w/ having a small loop of it going 5" above the waterline and my habit of doing my CO2 when I'm in the middle of a PWC.
2) CO2 is a fairly corrosive gas. Cheap plastic check valves won't stand up to it indefinitely, so if you do use a checkvalve, use a brass one.
3) Aquarium water getting into your yeast brine really won't hurt anything. You're going to have a much larger headache if your yeast brine gets into your tank, which a check valve will not prevent (unless it's installed backwards which means it won't let CO2 into the tank either).

 

[jflng]

Up to you. Like they said, pet stores sell them cheap enough. I would recommend placing a separator bottle inline with your setup however.

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