Last night I noticed that my skimmer was not putting out nearly the same amount of skimmate or bubbles as it had a few days prior. I made sure the venturis were clear with the suck the fresh water test. That is when I noticed how weak the sucking was. This prompted me to remove the pumps to inspect them. When I took off the cover I found shells in between the needles on the wheel and even some coagulated super glue (from glueing down corals the other day) that needed to be removed. I removed the gunk, rinsed things down in RO and hooked the pumps up again. The Alpha is running like a champ once more!