I called vertex too. Have been running my system 24/7 for 4 years now. This year my pond water quality is very good. Have been using two double membrane diffusers Bacteria and aqua shade. Beach area and shallows cleared up and it seems that organics are better controlled this year. My pond renovation is going on its 4th year and my bluegills and bass are doing well.

"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." Doug Larson