Hello to everyone. My wife Marilyn and I have had ponds of various sizes and with various fish for over 25 years. We currently have a 10 ft. round about 30 in. deep pond with 9 koi and I know it is not the best but 4 red ear slider turtles. "cute little guys". We live in So. Calif. and have always had a problem with algae. We met Dr. Dave a week ago and have already built the bio-filter. Wow can't wait for clean, clear water. We also have about 100 fry that are 34 days old and doing great; we have them in a 40 gal. tub. I do a 20 % water change every 2 days and feed them crushed to power koi food. I left the plants that the eggs were on in the tub and they enjoy the shade and privacy that the plants offer.