I played with the Durso system for over a year before giving up. <See my reply to you in your other thread.> the main problem is that your pump output changes ... with evaporation (so different water level in the sump), a bit of dirt or algae, etc... Even if you get the Durso perfectly tuned, it goes off after a few days ... so I am forever making the hole bigger & smaller. I finally tried an adjustable "hole". I siliconed an airline tubing in a larger hole in the cap, and attached that to a needle valve so I can control the siphon. that worked, except that I have to fiddle with the valve every day or 2 .... So now I run a 2 standpipe full siphon setup & have to do an adjustment maybe once a month.
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.