These bodies of water are often deep and tend to stagnate during the summer. Summer stagnation is caused when cooler, more dense water settles to the pond bottom. This deep water is often deficient in dissolved oxygen. Large volumes of oxygen deficient water may cause fish kills during fall pond turnover. Warmer water remains at the lake's surface causing lake stratification, a layering effect created by different water densities.
Water density is determined by temperature.
A stable winter environment provides conditions which are appropriate for trout production. The growing season is approximately 120 - 150 days, from early to middle November to late March or early April. The most popular cage design is cylindrical in shape, and is constructed of plastic mesh. The cage has both a diameter and depth of 4 feet, and a volume of 50.26 cubic feet or 376 gallons. To build a cage cut a 4 foot wide x 13 foot long piece of plastic mesh from the roll.