Ya I have taken them apart and cleaned them. Just recently infact becuase I thought that was the problem. It did help, however it didn't solve my problem. When you say cotton balls, do you really mean cotton balls? I've got a sequence power series 8500 on the skimmer. The skimmer is 9 ft tall with an 8" tube. Its a monster, and I've had it running for some time. The thing is, there are two injectors really visible when you look at the skimmer and they do great, its the ones that are kind of in the back that aren't doing what they should. I gotta get some pics up, forgive me, actually I'll do it now.