How much work is it to maintain a pond?
That depends on your pond size and type. In general, larger ponds are less work as they are more stable and take longer to get dirty. Also, well-filtered ponds with a skimmer and a biological filter stay cleaner, with the filters (rather than the pond owner) doing the pond maintenance. Ten minutes per week is average for general maintenance, except for when starting up the pond in the spring or shutting it down if desired for a long, freezing winter.
Do I have to add fish and if so… how many?
No, you don’t have to add fish, but they do eat mosquitoes and are recommended. They are very easy to care for, help eat pond algae, and can be trained to eat out of your hand. They add color and personality to any pond. Be careful not to buy too many or let them outgrow the size of your pond or the filter system. The rule of thumb is one inch of fish per square foot of surface area. Example: a 10’X10’ pond with 100 square feet of surface could therefore support about 20 five-inch fish. Koi ponds with extensive additional filtration can usually be stocked with much higher fish loads. Just remember that fish grow, but filters don’t.
How do I protect my pond in cold weather?
In the event of really cold weather (30º F or below) turn off your pumps. This sounds like a bad idea but when you have pumps moving the water during cold weather you are mixing the warm water from the bottom of the pond with the much cooler surface water. When the cold weather passes remember to start your pumps back up. If you have an external filter it is safest to drain it completely of water. If that is not possible, then place blankets or other insulating material around it and any exposed pipes leading to it or any auto-fill features you may have. If you have a disappearing water feature, you should drain all urns or containers of water if possible, or again, insulate with blankets.