# DIY yeast co2, do I set the bottle level with the tank? can i leave under the tank?



## trantran (Jul 3, 2008)

do I set the bottle level with the tank? or can I leave it under the tank where my filters are?


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## SpeedEuphoria (Jul 9, 2008)

I'm pretty sure you dont want it below the tank as it will siphon and make a mess. If you dont have room at tank level I know someone found something simple to hang it from the back of the tank but I cant remember where i saw it


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## davemonkey (Mar 29, 2008)

You can also put a check valve on the tubing between the bottle and the output end. That way, if a siphon were created by a drop in pressure in your CO2 bottle, the check valve would prevent tank water from flowing into your CO2 bottle. (I keep mine below tank level and rely on a check valve.)


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## longbowaj (Nov 25, 2007)

I have mine below the tank with no check valve and have not had a problem. I experimented with it some first to see if a siphon would be created. I'm not really sure why i never had a problem but I will say i usually use warm/hot water and i get bubbles in maybe 10mins.


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## Bert H (Mar 2, 2004)

Check valve is strongly recommended. All it takes is one time that a siphon is created for whatever reason to make it worth having one. Of course, ymmv.


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## longbowaj (Nov 25, 2007)

Yeah I knocked on wood as I wrote that reply.


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## Left C (Jun 14, 2005)

*Re: DIY yeast CO2, do I set the bottle level with the tank? can i leave under the tan*

I have my 24 oz separator bottle and my 3 liter yeast/sugar/water mix below my aquarium. I use check valves like a few folks have mentioned.

I keep both of my bottles in a Rubbermaid rectangular plastic mop bucket. I have a small submersible heater in the bucket to keep the water temperature around 78° F year round.


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## cbwmn (Dec 18, 2007)

I bought several check valves from LFS's. None stop backflow.

Does anyone know where to find a good one?

thanks
Charles


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## ghengis (Jun 11, 2008)

*Re: DIY yeast CO2, do I set the bottle level with the tank? can i leave under the tan*



Left C said:


> I have my 24 oz separator bottle and my 3 liter yeast/sugar/water mix below my aquarium.


Same. I do not use check valves, though, for the simple reason that my separator and 2L bottle both have lids on them.... If a siphon is created, how much water is realistically going to leave the tank? 2/5ths of not much, by my calculations... Probably just enough to fill one or both of the bottles, then the siphon will cease.


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## hoppycalif (Apr 7, 2005)

Brass check valves work a lot better and last a lot longer than the LFS plastic check valves. And, now we have at least two places to buy them:
http://oregonaquadesign.vstore.ca/index.php/cName/fertilizer
http://www.bestaquariumregulator.com/CO2.html#check


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