| My only big water body experience was a pond shaped like a bowl. It was or is 75 feet in diameter, 9 feet deep at the center, carved out of rock with a 4 inch pour of concrete with fiber rods for reinforcement. No plants, fertilizer or run off. A 12 inch bottom drain that flowed to another pond. 12 koi about 14 inches that grew like weeds, that's it. I ran a 1 horse Sta-rite sprinkler pump into it for 20 hrs a day, so that was about $1.75 a day I believe. Full sun exposure and I could not believe how clear that big body of water stayed. I never did figure the gallons |