Yours looks good! One difference is that my HOB intake is not sealed to the PVC pipe, it just sits in there. I'd thought about using larger diameter pipes to allow for a better flow/less restriction but even the next larger diameter pipe looks out of place. Atmospheric pressure will keep the water level inside the pipe at the same height as the tank as long as the pipe is not blocked. If the inlet gets blocked the water level inside the pipe will decrease until the HOB intake sucks air. Then the pipe will need to get cleaned, but it's relatively easy to remove as it's not sealed to anything.
I've already noticed some small detritus being drawn in at the "in" end. I'll see if I can find a fairly coarse sponge to put over it as I've found that sponges can quickly decrease water flow. And both ends can be detached at the bio-balls so I can clean the pipe by popping the "out" end off and putting the vacuum over in the "in" end to drain it backwards.
Last edited by PICKLES; 01-08-2013 at 09:08 PM..
Reason: adding details