Yeah, when I raise fry, I change the water daily for a couple weeks while I'm pumping them full of food. As long as the biofilter stays intact, you could change 50% of the water every 3 hours and it shouldn't hurt anything. A good majority of the bacteria live in the actual filter media and on other surfaces. Doing water changes doesn't deplete anything other than harmful contaminants in the water.


,I believe the problem was the fish went down backwards and was stuck in there good