I've had this protein skimmer running for over 6 months and it works great! However, recently I've noticed that it just stops flowing randomly and has to be re-primed to get it going again. I have to pull the air tube off the silencer and suck the water up with my mouth to get it flowing and bubbling again. Its been doing this about every other day for the past week and I have no idea why. I'd rather not get fish tank water in my mouth all the time so any help would be great! Anybody else have this issue?