[impur]

Originally Posted by ErikS

Wow, overall I don't think you could be more wrong if you tried.

As quiet as a full siphon? No, but a durso can be relatively quiet.

Reliable? As reliable as it gets. That's the beauty of not running a full siphon - it can flow far more than when it's running correctly (i.e. it will siphon -> break -> siphon). Unless there's huge obstruction in the line it will not fail. They have been in use for far longer than either of the full siphon methods..............number of fails other than a clog? Never heard of one.

A 1" durso will flow about 600gph, not 350 for 1.25". Far less than a full siphon but far more than you state.

OP - the best way to get a Durso quiet is to drill holes in the cap/top of the pipe - the part above the T. Drill 4 holes through both the cap & the pipe. Now you can turn the cap to adjust the airflow. Turn down the airflow until you get the siphon/flush -> open it up a tad, it will be as quiet as it will get. When you hear the air sucking sound you have it too far open.

This is great advice and what I do on my durso, using several holes and turning the cap/plug until you get the perfect mixture. I'm running about 550gph thru my 1" durso and you can't hear it even if you stick your head in my sump. The #1 thing people say when they come over to check out my tank is how quiet it is. I have never had a single problem in over 9 years using a durso.