Originally posted by southcoral
so how does a power head work exactly? if it doesn't put bubbles out then how does it get oxygen inside the tank? sorry, like i've said i've never had a salt water tank before so i've never seen one. And, how is it killing fish?? thanks a bunch love ya
They don't directly oxygenate the tank. They are, however, often used to create turbulence at the surface, which increases gas exchange.
The "killing fish" seems doubtful to me. I agree with ReefNut that dead or sick fish probably floated to the powerhead intake. The only time I've ever had a fish wind up on a powerhead was a foxface that was already declining, due to other factors.
I *have* had powerheads kill lettuce slugs, which is one reason I won't buy them any more. They're beautiful little animals, but completely unable to keep themselves out of powerheads, overflows and other hazards of the aquarium.