Thanks for the input everyone. In reply to Mebbid's post, What are HOB
overflows? Diameter of PVC
is 3/4 inches. Flow is 60 gallons/hr. The sump is part of a trickle down wet/dry filter for turtles because I found commercially available filters and pumps inadequate or prohibitively expensive.
In reply to Dylan P. There is a word attachment with my original post with a diagram. I will try to post a picture if I can figure out how to do it from an iphone. The system seems to be working a little better with a a couple inches of water in a short 1/4 in tube coming off a $2.99 air check valve goop cemented into a 3/16th inch hole drilled in the utube going over the tank wall. Do you know where to procure decent self sealing air check valves for pvc
? The inflow pipe is below the outside T fitting which has one branch leading to a trickle filter/sump and the other to a standpipe. Could that be a problem? Is the hole in the cap of the standpipe too small at 1/8 inch?