Here's a calculator to figure how many gallons your pond is. http://www.pondvolumecalculator.com/ Fish need shade when the water is 80 degrees. Keep algae down as it robs the water of oxygen. With no aeration figure 1 inch of fish per gallon. When aerated you can increase that quite a bit. If your fish are at the surface gulping air (except for koi types), they need more aeration, or fewer fish.