I had a prizm...probably the worst skimmer you can buy. It worked fine for a few weeks, but didn't skim very much...then it quit skimming, so I increased flow a smidge. 20 mins later my cup was full of water.
Turned it back down...the next day it broke it's siphon.
Then it ran normally, but again didn't produce much skimmate, and any attempt to slightly increase it resulted in mostly skimming sea water.
However, the perfect fix was to throw it down in the basement, and put a CPR bak-pak on the tank...or any other skimmer that actually works.
Former advisor and planted tank geek...life's moved on though.