i know 2 guys that have them
one guy runs one on a 240 gallon from his basement
the other guy runs one on his 450 gallon from a 400 gallon sump
they flow a lot and need to add a lot of baffles if you are going to use one
the guy with the 450 had one hooked up to a 150 stock tank and it kept pulling bubbles back into the tank unless was run at half throddle