Hi Alice, Thanks for your great questions.
"I have a couple questions about winter care....I have a healthy, active school of about 15 goldfish and a frog! I have a de-icer that I am planning to use. .... I live in Massachusettes. "
Q:
Do I need to continue to run the pump/filter during the winter?
A:
Depending on the climate in your area you may or may not want to operate your pump/filters during the winter. If the temperatures stay mostly above freezing then it will be beneficial to keep your pump/filters running through the winter. Pond bacteria are not active due to the low water temperatures; however, it will stay alive as your pump continues to oxygenate the water. Operate your pump at a minimized flow rate. You can help accomplish this by turning off bottom drains, turning the flow rate down on your pump, and if possible, placing the intakes to your pump/filter at mid-water level. Note, intense circulation in the winter will mix the cold surface water with the warmer bottom water which can potentially harm any aquatic life during the over wintering.
Q:
Should I remove plants? water lily, bamboo? cat tails? the pond is 9' x 5' with an aprox 2' deep floor that has an aprox 3' deep 2' x 2' center. The cat tails are in the center deep section. The other two plants are in the 2' section.
A:
Pond plants will need to be cared for based on type. Any oxygenating/submerged plants should be left completely submerged at the bottom of the pond below the ice line. Floating plants (such as water hyacinth or water lettuce) should be removed from the pond as they will die during the winter months. Make sure you don't leave any dead plants in the pond as they will decompose and rob the water of oxygen required for any over wintering aquatic life.
Because your pond is at least 2' deep, any Hardy Lilies and marginals should be cut back and placed in the deepest part of the pond. This should be done after the first frost.
Other hardy water plants such as Iris, Sweet Flag, grasses, Cattails, etc. should be left in place to over winter regardless of pond depth. I recommend cutting back the foliage on these plants in the spring rather than in the fall.
As for all tropical plants, they all must be removed and placed in water that will remain above 65 degrees. I recommend doing this well before the first frost.
You can find additional information on Winter Care for Garden Ponds here: http://www.bestfish.com/wntrpond.html
It's great to hear that you have and intend to use a de-icer during the winter months. Your fish will thank you greatly for it.
