Garden Answers

Ponds

 

Question: We've really enjoyed our new pond and goldfish this year, but are worried about keeping our fish alive through the winter. Is it okay for the surface to freeze? Do we need a heater?

Answer: You shouldn't have to make any drastic changes to keep your fish happy over the winter. The exceptions to this are if you have a very shallow pond (less than about 2') or if your pond is in an above-ground configuration. That's an entirely separate issue! It's fine (and normal) for the surface of your pond to freeze, and that doesn't affect your fish. They should be staying at the bottom of your pond now anyway, going into a dormant state that will sustain them throughout the winter. My pond contains a filter (which I clean out well in the fall), pump, and a concrete frog spitter that keeps a small section of the pond from icing over, and more importantly, aerates the water. This aeration insures that any left-over debris at the bottom of the pond doesn't leach all the oxygen from the water and stifle the fish. When temperatures drop, I have the added bonus of a very cool ice sculpture emitting from the spitter!

I'm cautious about recommending heaters for a pond, primarily because it's very easy to overheat your water. If you want to use a heater, the trick is to find a heater that has reliable settings which allow it to maintain the same temperature (preferably just a little above freezing) throughout the winter.

 

Question: What do we need to keep our pond healthy and clean?

Answer: Small backyard ponds need three things: mechanical filtration, biological filtration and aeration. Mechanical filtration is just a filter element that helps strain out the debris that accumulates in a pond. It can be made up of a plastic mesh or sand. You’ll need to clean out your filter every three to six weeks depending on the size of the filter, the size of your pond, and how dirty your water gets.

Biological filtration is exposing the water of your pond to a couple very necessary and beneficial bacteria. All ponds accumulate organic matter at their bottoms. This “sludge” will decompose and as it does, it releases ammonia which is toxic to fish and plants. These good bacteria break this ammonia down into nitrates which help your plants and fish. There are a lot of different biological filters and many are built into a mechanical filter. There are even homemade rigs that you can find out how to build on the internet.

Aeration is simply the mixing of oxygen into your pond water. This naturally happens at the pond’s surface, but having something that will splash the water in your pond will help maximize the addition of oxygen. You can do this with either a small waterfall, a little figurine that shoots water back into the pond or a spray head that shoots water up into the air to splash back down into the pond. Whatever it is, splashing the water is a good thing!

All three of these things I’ve mentioned need moving water to function. For most people, this means a pump which entails having electricity out at the pond. That may be a problem for you, but it really is the best way to maintain a small pond. Now, the bigger the pond, the easier it is to maintain and the less need for these three things. It’s still necessary to have some water movement, that is, having some water move into the pond and some moving out. If you think about it, that’s how most natural ponds work.

A good pond set up will take care of itself naturally. I hope this helps.

 

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755 26 Road (North 1st at I-70) • Grand Junction, Colorado 81506
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