Safely removing oxygen

[MCsaxmaster]

Randy,

Is there anything you can think of off-hand to lower the O2 level in an aquarium in a predictable way (e.g. lower it 20% vs. 30%) without markedly affecting other water chemistry parameters? In particular I'd be worried about doing something that also causes CO2 to gas off. Just to be clear this would not be in a recreational aquarium. The purpose would be specifically to address the effects of lowered O2 on organisms.

Chris

 

[Randy Holmes-Farley]

The only good way that I can think of is to aerate with gas mix that has normal CO2 but is deficient in O2 to various degrees. Not a simple DIY, however. There probably are chemical means to lower O2, but I do not know of any that would not themselves be a concern with respect to organisms.

 

[MCsaxmaster]

Ok, I guess that makes sense. Initially I thought of bubbling N2, but 2 seconds later realized that would also drive off the CO2 and do bad things to pH. Thanks though.

 

[Randy Holmes-Farley]

You're welcome.

Let us know if you come up with anything else!

 

[MCsaxmaster]

Okey dokey. Not a project I can do now, but planning for the future I suppose. I'll see what I can come up with.

 

[Mimbler1]

What about bubbling N2, but also adding Co2 through a PH controller? That way the controller would keep Co2 where you wanted it,
Mike