I need help:(
I have a 10 gal aquarium and 7 Koi. 4 are babies, 1 is approx 2" and the other 2 are approx 4" long. My water is neutralized well water, and the fish are fed once a day. The inside of the tank has a brown film and the water appeared to be hazy. I added 2 teaspoons of "stress Enzyme" to replace some of the bacteria that I may have lost during cleaning. I have a pump and bio wheel that hangs on the side of the tank. Can someone please tell me, how to clean the tank on the inside without having to dump the water once a week.:( I don't like using too many chemicals. The filter is cleaned every other day or so, and is replaced once a week. I have been told to add plecos and a snail to keep the gravel clean of waste.
Thanks!

Even at their current baby size, the koi are way overcrowded in your 10 gallon tank. Can you find them a 50 gallon tank or indoor pond or something? The brown film on the inside of the tank may be brown algae (diatoms) which are easily removed by wiping the tank with an algae pad or even a paper towel.

I suggest getting a gravel vacuum and vacuuming and removing 50% of the water twice a week. Replace it with new water with some aquarium salt (a tablespoon per 5 gallons or so). Add some more Stress-Zyme weekly.

Adding plecos or snails is a bad idea as the tank is already so overcrowded. Plus, smaller plecos may suck on the koi. The koi may also kill snails by pestering them.

I assume your baby koi will go out to a nice big pond in the spring?

Good luck!

Thanks Robyn:
Yes I will get a bigger tank and yes they are going out in a nice big pond in the spring.
I appreciate your reply and will do as you suggested.
Regards,
Liesel