Hello to all:
I'm new to this site, left an intro explaining the situation, but I'll reiterate.
My girlfriend hopes to over Winter a 1/2 doz 3" Koi in a 39g bowfront Topfin aquarium. The filtration system is wholly inadequate, we're having to do major H2O changes every 3rd day. I made a gravel vacuum, it's incredible the amount on trash the rascals generate.
I seek advice on an filtration set-up. I've read enough about Koi to know their not suited to captive living, but my gf is set on keeping them. Thanks