# Ehiem CO2 diffuser



## Sir_BlackhOle (Jan 25, 2004)

Does anyone know how much pressure it should take to make the ehiem diffuser work? I have it hooked up to DIY CO2 now and the bottle gets full of pressure, but no bubbles come out of the diffuser. I am afraid the bottle is going to explode....any ideas? I hooked up the diffuser just like the pictures on the back of the box.

TIA


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## Wheeler (Feb 8, 2004)

Sorry SBH, you're prolly not gonna get that thing to bubble with the wimpy pressure that a yeast generator will provide unless you can find a way to prevent your seal from breaking. Even then your bottle (unless it's glass) will break before you have enough pressure

Don't believe me? Just blow air into the hose that feeds into the diffuser and try to make it bubble. Good luck :? 

That device makes such tiny bubbles because the pores in the sintered glass are very tiny. It was meant to be used with pressurised set-up.

For a similar effect that will work with your DIY set-up, try one of those wooden air stones the reef guys use for the skimmers. They're a little pricey, but it should get the job done in a similar fashion.

Can I ask why you're not using the intake of your filter/powerhead to diffuse the gas?


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## gpodio (Feb 4, 2004)

How long have you waited for it to build up pressure? I say this because with a CO2 tank we run around 10-15psi, that's not a lot at all... To break a soda bottle you will need a lot more than that. If a yeast setup can burst a bottle, and trust me it can, there should be no reason why it can't push CO2 through the glass diffuser. That is if you find a good way to seal the airline tube to the bottle lid. If your connections and seals can stand the pressure, the bottle and airline tubing certainly can.

Giancarlo Podio


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## Wheeler (Feb 8, 2004)

I couldn't get mine to run at less than 15psi, and when it started to clog it got worse.

That diffuser is a POS, IMO. Further, I couldn't get my bottle seals to stay sealed when bubbling it into the filter. I dunno, I guess it could work..


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## Gomer (Feb 2, 2004)

I'm currently running DIY co2 through a bioplast atomizer...pretty similar in concept. sometimes it only takes a couple hours, last time, 1/2 a day before CO2 came out. I personally think my check valve will blow off before the bottle explodes.


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## Steve Pituch (Jan 25, 2004)

Kevin,

If the Eheim diffuser came with a check valve, throw it out. It actuates at about 15 psi. A tetra check valve available from Petsmart actuates at about zero psi.

Try blowing into the diffuser without the check valve. If the resistance is too great because of that narrow tubing and nipple, I can trade you for my diffuser. I replaced the narrow nipple with a wider one that accepts regular airline tubing. The resistance should be less. otherwize we need to devise a way to feed the co2 directly into the intake of your 2217.

Steve


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## Sir_BlackhOle (Jan 25, 2004)

Steve,

Thats exactly what I ended up doing. I couldnt blow through that check valve, and when I took it off and used the cheap one it started working. Its actually working very well now. I have posted a new pick of the tank in the general forum.


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