How many gallons per hour are you looking at though the filter and is there any calculations for the perfect rate for the bacteria to thrive though the media?
Depends on the type of filter. For aerobic filtration - where it’s pushes ammonia through the nitrogen cycle to nitrate then the plants take nitrogen out.
Typically it’s a multiplier of pond volume per hour. The smaller the pond the faster the rate. The bio is sized in surface area, so varies with media. The media works out at about a 50l of media for the size of the pond. I could add more as the bio tank will take more.
For my small pond it’s ~1500l so I run the pump between 6-8,000lph. This presents the waste to the bacteria that grows on the media.
the new pond has a different filtration system. Called Anoxic filtration it uses bacteria that works in very low oxygen. They convert ammonia to nitrogen gas without going to the nitrites/nitrates. In that filter one basket per fish. The water passes slowly past the filter. With this I don’t need the bio, as the two filters will compete. The benefit of anoxic is I don’t need to remove the nitrates.
Max flow per 110mm pipe is about 15-18,000lph. So 30-36,000lph however as it’s gravity fed and airlift so it needs a low restriction. However easing off the air will slow the flow rate.