How deep are your ponds in Florida? I imagine a constant hot climate is a challenge to keeping fish safe and cool is a problem. As part of our pond maintenance we do frequent water exchanges by letting the hose run in the pond for about 10 to 15 minutes several times a week the water flows out of the pond, thus it's a water change. In hot weather we do the water exchanges every day. Fortunately for us water is inexpensive and we do not need to add de-clor.