i bought a skimmer online and it didn't come with instr. when i turn it on little air bubbles go back into the tank, is this suppose to happen and will it put bad things back into my tank.?
Number one it would help all if we knew what type and model of skimmer you bought. Please let us know ok. Also, I figure that your new at this and it probably is a air stone protien skimmer, did you attatch an air stone? Try and post a link to what make and model your skimmer is ok Good luck