I get going after the pond is warm enough to put my arms in without much cold and pain. As I recall for 7b that is sometime in late April. Every year or two, I yank out all or most of the water lilies and some of the Sweet Flag clumps around the edges. I re-pot some of these. I also set out a garaged or housed Elephant Ear or two into a shallow area.

I usually do a 1/3 water change because I figure the water has lots of fish poo and stuff in it. Then I check my water lilies and repot if needed, put in fertilizer tabs. Move the non hardy plants from the sunroom to the pond. Start up the pump. I can't wait for the water to get warm. April 15th is our usual date of last frost but I usually jump the gun by a couple of weeks and get everything going when I am out of school during spring break. I also plant my garden and cover things if a frost comes. I can't wait for warmer weather.

We live in Northern Virginia (7b) and leave our pond (900 g) going all year long. The pond covers the width of the backyard of a townhome overlooking a golf course. We use a pump to move the water from the pond to the top water fall where it spills into a bifurcated stream that then meets in a small ponding area and drops from another waterfall into the large pond.

So, for maintenance in the spring and fall we check to make sure vegetation hasn't started growing into the pond. From time to time, tree roots will try to invade by growing along side the liner and then into the stream. We clean the settled leaves from the bottom of the pond with a skimmer, the excess mud out of the stream and then with a scrub brush clean the filter on the end of the pump. I also thin out the irises that grow in the ponding area as they can completely take over. This takes about a half day in spring and again in the fall. Once or twice a month I check the vegetation and check for algae growth. Weekly I check the water levels and the PH once or twice in the summer. This weekend it was in the 60s so I did all of this in a Sunday afternoon.

In winter, the water movement keeps the pond from completely freezing over. It may look frozen on top but the water continues to move underneath. Often an ice layer forms over the pond but there's a cushion of air between the pond water and ice layer so it stays insulated, it doesn't get cold enough for the pond to freeze completely over. Over the years we've used a pond heater, an air exchanger and bubblers which helps keep the pond from freezing over and also helps to aerate the pond. I find that the bubblers proved to be one of our best assets and we now keep them going all year long. Hard to believe they have lasted so many years in all kinds of weather.

We also put a mesh screen across the pond in the fall to capture the leaves; it also helps to keep critters out during especially cold winters. Raccoons are crafty, they devastated our pond one year when we weren't careful about how we laid down the screen. We didn't want it to get all caught up with the ice that formed along the waterfall. That was a mistake!

Let me know if you have any other questions. Am glad to help!

It's really such a wonderful addition to our life and has been fairly easy to maintain. It's a natural part of the landscape and has worked out so well for us.

FYI, keep koi, fantail goldfish, shubunkins, tadpoles/frogs, snails and other aquatic plants so that there is a natural balance. The pond has attracted a significant amount of wildlife from visiting turtles, birds, skinks, and the occasional snake and/or raptor (the small birds seem to attract the winter raptors). Since water flows regularly we've never had problems with mosquitoes though we did also purchase mosquito fish just in case.