hi everyone,
i just got a rena filstar xp3. initially when i set it up it was extremely silent. after a few hours some air entered into the filter and now it makes a trickling noise. is it OK for a little air to be in there?
i use to use a zoomed 501 filter. then it burnt out *i believe* because it got air in it. then i got another 501 and again the same thing happened. now i am paranoid about air.
thanks for your help



