A circulation system for bodies of water. In one set of embodiments for larger bodies of water, modified horizontal plate designs are provided at the entrance of the draft hose. The plate designs have sections that pivot downwardly as the flotation platform and depending draft hose are rapidly raised in high wave conditions to let the water escape downwardly out of the hose. Adaptations to the floats for the elongated arms of the platform are also made to essentially eliminate the creation of any damaging torques on them from high waves. Another set of embodiments are particularly adapted for smaller systems in municipal water tanks for thorough mixing of the water and treatment to kill undesirable ammonia oxidizing bacteria and prevent or at least inhibit their return.