post this on rec.aquaria.freshwater.goldfish or
rec.aquaria.freshwater.misc - you'll get more replies than
on this newsgroup

EGMono wrote:

I'm still new at aquatics and although I've been reading a great deal, and
learning quite a bit, I have a million questions...like this one.

I understand (basically) how a protein skimmer works. The bubbles coming up
make contact with water coming down and carries proteins out into a collection
cup. Correct?

Does it only work with sal****er tanks? Why?

TIA,
--
E.G.Mono