Laguna Floating Pond Heaters and Aquadyne Rhino II heavy duty bottom drains.
This is the only vacuum on the market really capable of cleaning average and above-average sized Koi ponds. It features two pumps: one to suck up water and debris (muck) and one to pump water out of the discharge hose either back into the pond, or up to 32 feet away into a garden or flower bed. You can use both pumps at once for continuous cleaning, or just one at a time to function like a standard shop vac
Pond Heaters– designed to safely keep a hole in pond surface ice during winter to allow for crucial gas exchange. If the pond is allowed to freeze over completely, hydrogen sulfide gas, produced by anaerobic bacteria in your pond, will accumulate and kill you fish starting with the largest individuals.
Bottom Drains-one of the most important features you can add to your pond. There is no substitute for a properly installed bottom drain for preventing the build up of harmful muck on the bottom of your pond.