look it is a 50g new tank which has 2 clowns, 1 Gobi and a few cucs not much of a bio load and the water has not hit saturation, it is working fine once he adds some corals and fish it will skim some nice dark skim. by the way the older one have a venturi that is cut on an angle with on holes. I have both types and they both work just as well as the other one.

Bill