Nice to make your acquaintance. I never did get the gh pump. I got an eco air 793gph pump and it did the trick with those bubblemac stones. I have since moved on from dwc to perlite hempy but i still use the pump and stones in my cloner. As for the stones... I got 4 of the 4inch long ones. They're still the best air stones ive been able to find. They cleanup like new with a short bath in muriatic acid.