Hey everyone, Just wanted to show some pics of a modification I've come up with for a Durso-inspired standpipe in a CPR overflow. I tried this design first: http://home.att.net/~rstockman/overflow.htm However, there was too much turbulence created as the water flowed through the holes. I then tried the square notch in the standpipe in place of the holes, but this was no better for me. I had turbulence and, hence, loud noise. I tried to come up with a way to create more laminar flow down the pipe. I thought why not just put another tube in there to break up the turbulence. I toyed with some flexible tubing at first but then discovered CPVC. I use 5/8" CPVC tube inside the 1" PVC standpipe. I reamed a hole in the original PVC cap large enough to accept the CPVC, then capped the CPVC with the appropriate cap with some holes drilled in it. There's some pics below. I have a 600gph CPR overflow matched with a ViaAqua 3600 pump in the sump. I guess we're probably getting 400-500gph of flow, and this standpipe has handled this nicely.