I have an indoor pond about 100-125 gal, one of the kidney shaped ones. I run 1-250 gph pump placed in filter box with buffing pad material around for mechanical filtration. It pumps up into a 5 gal bucket at top, tee'd off for dual flow across top, water goes down through some plastic deer netting and lava rock for biological, then outlet pipe runs from bottom up to top and out a 2" pipe. I have 3 turtles and 3 goldfish and it filters fine, pond stays pretty clear.
As far as a venturi, I can not help on that one. May try an air line anywhere in the return line? While the inlet would be great for media, you are oxygenating water, it would help no matter where it occurred. You could always plug with SS screw/sealant if it doesn't work.
One caution with those bucket lids, don't put much more flow than what you have. I am on a DIY fish site, guys have stated much more pressure that 3-350 gph pump will blow the top off or start leaks. I had mine set up with drain double size of inlet so I built no pressure lid just sat on there. I loved my bucket filter, but the plastic got brittle and cracked at bulkhead. I just built a large canister out of 4" PVC drain pipe.
As far as a venturi, I can not help on that one. May try an air line anywhere in the return line? While the inlet would be great for media, you are oxygenating water, it would help no matter where it occurred. You could always plug with SS screw/sealant if it doesn't work.
One caution with those bucket lids, don't put much more flow than what you have. I am on a DIY fish site, guys have stated much more pressure that 3-350 gph pump will blow the top off or start leaks. I had mine set up with drain double size of inlet so I built no pressure lid just sat on there. I loved my bucket filter, but the plastic got brittle and cracked at bulkhead. I just built a large canister out of 4" PVC drain pipe.
