Hello, I just purchased a new bio -filter. I have not yet installed it, as I want to make sure it will be the appropriate size for my need. I have a small home made pond ( rubber liner and about 300 gallons). We have 7 large Koi and feed them almost daily during feeding season. The bio- filter I purchased is the VIVOHOME Pressurized Biological Pond Filter, 1840 GPH. Is this a fine enough Bio-Filter, or is there something more appropriate I should consider?