Don't buy prizm for $90. I got mine for $60. REgardless, the product sucks. You won't get a good skim out of that product. You'll get, like, tea-colored skim. But most good and fairly affordable skimmers out there skim dark coffee.
Prizm is a bad skimmer with good lies behind it. Don't buy it! Not even the pro series. It doesn't matter. First off, it doesn't have a needle impeller than allows for tinier bubbles. It has like a multi-blade regular impeller that you can find in most powerheads. Not worth the money, I tell you. And I own one right now.
We live and we learn