i have a reef octropus 200 int classic skimmer about 2 years old. that has a aquatrance 3000 pump on it. ive noticed the pump acts kinda wierd. seems like the output will vary and fade in and out. it will be skimming normal then all of a sudden like turbo mode and has a noticible hum coming from air silencer. also the output water starts splashing more. has anyone else exsperienced this with there skimmer? is it a sign of a bad pump?bad impeller? completely dis assembled and cleaned and it looks fine no build up or broken impeller needles.