I have about 150 baby koi, almost 2 weeks old in a 10 gallon aquarium, I have a bubbler going all the time, and feed just a tiny pinch of food about 4 times per day. Anything they don't eat, naturally goes to the bottom and grows stuff. I have sucked the bottom out, almost every day, but worry about the water quality. At what point is it safe to put in a water filter. Tried it last night and the poor things were just tossed around that tank, so I stopped it. When I suck the old food stuff out of the bottom, I get more water out of the pond and add it to the tank. So I guess you can say that is a partial water change.

This is so exciting, the first time I have tried this. A year ago in January, a blue heron ate all the koi I had, which were about 8 years old. During the pond tour, I got lots of donations of koi that were too big for other ponds and now have a total of about 14, some of which spawned 3 weeks ago. Some are butterfly and very very anxious to see how many butterfly's I will end up with. I know to expect about 50% mortality rate between now and the future.

So for now, the water filter is my big question.

Thanks!

Kathy