Oxygen

[SierraReef]

At night, my clownfish stays right at the top of the tank - it looks like he's trying to suck air. Is this normal or do I need to get an air pump going in my tank at night? I've got a pump and could put it on a timer so it goes on maybe an hour after the lights go off and back off shortly before they come on. What do you guys think?

[Boogiechillin]

Hmmm....clowns are weird, so it's hard to say. Oxygen levels dip at night as all the algae and plants in the tank go into the dark cycle of photosynthesis and consume oxygen instead of CO2. But, if you have any surface motion - a filter return, a powerhead blowing across the surface, etc - this shouldn't be a problem. I wouldn't recommend an air pump as the bubbling will generate a ton of salt creep, and microbubbles can irritate corals & anemones if you have any.

[SierraReef]

Thanks Boogie. I thought everything was alright - just wanted to make sure. Plenty of surface motion, guess he just feels more comfortable up high and in a corner at night.

[Ray Pollett]

I have to disagree on the bubbles iritating anemones. I've seen more than one move directly over airstones in the bubbles. Ones been doing very well for 2 years.

Salt creep can be a problem.

Ray