nice drawing albert, you should apply at acad!
what do u mean "can't dial it in?"
do you mean the input from the tank is noisy, or where it's going to the sump?
here's an illustration of how I did my durso (this way is SO much easier, and cleaner looking than a standard durso):
if you find the water's rising up and down over n over within the standpipe, either drill a larger hole, or attach a piece of airline tubing. it means the water level's reaching higher than the air hole, breaking the siphon.
and for your return, this is what I wish I did, to stop most of the bubles, and get rid of the pip gurgle:
you can do away with "dialing in" your standpipe, by putting airline on the hole, then getting one of those powerhead venturi silencers... you won't hear a thing
