Like Dun said I have tied the float up and put in Corrid for coccidiosis treatment. Refilled the tank every day with water and more Corrid. You are correct, with the float active the meds are diluted as more water comes in.
Do you think it helped with the eye problems? Not sure you could get a large enough dose of antibiotic to have much effect on an infection but have never tried it. Another issue, if the problem is not inside the digestive system It is my understanding that some (possibly many) antibiotics will not pass thru the gut walls. I understand that is why most all scour meds are given orally while respiratory and other infections such as abcesses, etc are treated subq or im.