its running at about 250 gph
right now (just a 30 gallon fw
with the hole is a "durso standpipe", just very short compared to what you'd see in a in-tank overflow - here is a better picture of the durso, before I enlarged the hole
I hear ya on the clear u-tube ... but the cost breakdown
clear U Tube 1.5" - Approx $20 with shipping
white U Tube 1.5" - Approx $3 locally
I ran a similar white U tube for over 6 months with no air-pocket problems, so it's something I trust enough to not worry about.