so im setting up a 30 gallon medical tank for feeder fish, to help insure my gar wont die from anything. so what im wondering is when i treat the water with both pinafix and melafix, do i do a water change at the end of the 7 days. or can i leave the remidy in the tank, cuz the feeder fish that will be in there at the beggining of the week wont be there by the end of the week, and at the beggining of the new week a new batch of feeders will be there. or should i do a 7 day treatment on each batch of feeders i get in and change the water before i get the new batch of feeders in.. im sorry if this is comfusing lol. if anyone kinda understands what im saying any help would be great thanks