Hey guys. I have a situation. First let me start out by saying I have a 46g with many fish, I will be talking about my Koi. Then I have a 125g with a big CK who tried sizing my koi up for breakfast. With that said Im trying to get my KOI larger. I've had him in the 46g for 2 months and he has grown from 3in to 8in. Which is great but not big enough for the CK. Im tired of the high nitrates, when they reach 60ppm, which only takes about 4 or 5 days, I do a 75% water change. Also, KOI is the dirdiest fish I have own! Cuz the tank is high, its sorta a pain to remove the debris from the bottom, I also have decorations for the other fish. I was thinking of starting up my de-commisioned 30g and just have the KOI in there by himself. The question I have, I know what experience has told me, but Im a member of this awesome site and value all of your responses. I would like to try an Emperor series cuz I have a Penquin, two Aquaclears and a fluval canister. If I go with an Emperor 280, that will have a 9.3 turnover rate. If I go with an Emperor 400, that will have a 13.3 turnover rate. Can I have too much of a turnover rate is my question? Thank you.