Hi guys we recently purchase some goldfish about 11 of them my husband cleaned it and everything like the 4th day the tank was dirty lol. We have a fliter but i feel like it doesn't do much. If you have fishes can you recommend me some ideas or products that can help the water or tank not get dirty super fast? Or is that pretty much it with fishes?

Plse & thank youu.

Ps. Totally not baby related it but we really want to look for something that can help out.