How to prevent water backflow in CO2 setup?

[Alok]

I am running CO2 with solenoid, so it runs roughly for the same time the lights are on. However, when CO2 stops and starts dissolving in the pipe, the water starts moving towards the CO2 tank. It has actually moved into the oil bubble counter and this has resulted in an oily film on water once the CO2 comes back on. How to prevent this? Will a glass diffuser take care of this problem? Any other ways to prevent the water from siphoning back into the bubble counter?

[yikesjason]

A brass check valve is standard. The cheap plastic ones like you see at petsmart are not recommended.

[rickztahone]

A brass check valve is standard. The cheap plastic ones like you see at petsmart are not recommended.

+1, one of the cheaper parts in a co2 setup. check out Griggs' page for some brass ones.

[Bilbo_wh]

I agree as well.
A good quality check valve is very cheep compaired to the problems you can get by not having one.

[calihawker]

yep, yep. go with a good quality check valve.

[waters10]

Although I haven't set up my system, I think it's better to go with 2 check valves, one before and one after the bubble counter. Some built in bubble counters have built in check valves, but not all. I believe there's some risk of having bubble counter liquid entering your needle valve and/or regulator if you don't have a check valve before the bubble counter. I know Rex recommends this configuration.

[TankWatcher]

My bubble counter came with a built in C02 safe bubble counter. I also have a separate C02 safe bubble counter, as waters10 suggests.

[wesleydnunder]

+1, one of the cheaper parts in a co2 setup. check out Griggs' page for some brass ones.

+1
That's where I bought mine.

Mark

[Alok]

Thanks everyone, I will check out Grigg's page if I can find it! :o

As an update, I attached the glass diffuser yesterday night. Today morning I did not see the water in the CO2 tube, so I am assuming that the glass diffuser acted like a backflow preventer. However, I will just get another brass one, just to be safe. Thanks a lot again.

[yikesjason]

Just in case you have a hard time finding it, here is Rex's store.

http://www.bestaquariumregulator.com/CO2.html#check

[Alok]

Thanks Jason.

The glass diffuser did hold the water back for a couple of days, but now it is back in. :( I need to order that valve right away now! :o

[2wheelsx2]

If I were you, to prevent the solenoid and regulator from being damaged, I would either disconnect it and not run CO2 until you get the check valve, run out and get a plastic air check valve for now and use it until you get the brass one in place, or run the CO2 24/7 and use a timer to run an air pump and airstone when the lights are out.