prizm arejust slightly better than a skilter, I cused many times when it just stopped working and my nitrates went nuts. Horrible skimmer if you want good water quality, an ok skimmer is the water quality you want is barely average. I user my prizm to cycle live rock, nothing else. If you are going to get a skimmer, then buy a aquaC, it amazes me. Tunze is also very good. CSS are good, but not the best unless you double up or go overkill they can be fickle as well. When using a cheap skimmer (prizm) you really dont know what you are missing until you get a true skimmer.
my skimmer experience:
skilter: F
prizm: D-
CSS: C+
aquaC remora: A+
Tunze aslo gets an A from the reviews I have read