| I have always loved fish ponds, so one of the first things I did when I bought my first house was build a large cement pond. I built a pond in two later gardens, and of course built another in my present one, about eight years ago.
The pond is of solid cement, with steel mesh re-inforced walls about four to six inches
thick, roughly circular and eighteen feet across. Since it is nestled near
two huge cedar trees I could only dig down a short way before hitting tree roots, so the
pond is mostly above ground, with rock covered walls. It is about thirty inches deep in
the middle, and I once calculated that it holds about 3,000 gallons of water. I like all non-carnivorous fish, and have had up to eleven species wintering in the sometimes iced over pond, including koi, goldfish, golden orfe, common carp, brassy minnows, fathead minnows, redside shiners, sticklebacks, bitterlings, and two or three different types of tadpole. I was surprised a couple of years ago to find that two Myxocyprinus asiatica (“hi-fin sharks”) made it through the winter, but they died the following year. In the summer I have sometimes put a few surplus guppies and platys in the pond, but of course they don’t survive the winter. One summer I noticed some killifish in the pond. I didn’t purposely introduce them – their eggs must have been attached to some plants I put in!
Pond in early Spring Pond in June Despite all these species of fish the pond is by no means overstocked, and I have no mechanical filter, preferring a low maintenance balanced approach, with lots of plants. Due to the plants and the partly shaded location, I have never had an algae problem (apart from hair algae one year), and the water is always clear. During the summer I run a pond pump to aerate and circulate the water. I live near a natural river valley, and have two enemies: racoons and herons. Racoons used to pull out weed from the pond and generally make a mess, but are easily discouraged by an electric fence, which I bought from an agricultural supplies store. Herons are much more of a problem, and if they get the chance, these big grey birds will eat my fish in the winter, starting with the biggest of course, which is why I have never been able to grow my koi very big! I battle herons in various ways, but mainly by stretching nylon netting over the pond as soon as the lilies die off. If I leave this too late I am sure to lose fish! As well as this, I float a raft of wood in the pond in winter, so that the fish have something to hide under (and to counteract the expansion of ice). Also, all year I keep a webbing of strings across the pond just above head height, hoping to give the herons trouble in landing and quickly taking off. Finally, I have a realistic life-sized plastic model of a heron guarding the pool. I understand this is only effective if moved around regularly. Some people find that one or two strands of fishing line stretched around the edge of the pond discourages herons, since they don't land in the water but rather at the water's edge and don't like to step over things, but my herons seem to be particularly persistent.
I have another pond at my house – an indoor pond! I built this myself with a framework of 2”x 2” wood set on a 8’x 4’ plywood base, finished with fibreboard inside and out, and lined with a plastic pond liner. Lighting is simply four 4ft. grow lights suspended about 18” from the water surface. (April 2003: I doubled the lighting to see what would happen). Heat is from two 300 watt heaters. The filter is just a medium sized Fluval 303 canister filter (meant for only 70 gallons), and there are two powerful air pumps in opposite corners to add some aeration and water circulation. The pond is in a spare room in my basement (i.e. not in a normal public area, although I do of course show it to friends), so it was built in a utilitarian fashion rather than as a display piece. I keep the water about 15” deep, and calculate I have 300 gallons at this depth. An early problem was water condensation in my house, especially in winter. All my windows steamed up and mildew started to appear in the pond room! I solved this by building a “tent” of clear plastic over the pond. This keeps the moisture contained and has the added benefit of providing a cocoon of warm moist tropical-type air for emergent plants.
Instead of gravel I collected many bags of coarse sand from a local clear fast flowing creek, and spread it about 3” deep. I have had no problems with this – the plants grow well in it and can be easily planted. I have about thirty different plant species in the pond and they nearly all seem to thrive, emerging, flowering, and trying to crowd each other out. I have to thin out the dominant plants constantly, and of course have a ready supply of plants for my other aquariums.
I keep mostly poecilidae in the pond – guppies, mollies, platies and swordtails. Needless to say they breed like crazy (but indiscriminately), and giving thirty or so to a beginner friend makes no noticeable difference to the stock. I have a few other “friendly” fish in the pond – various species of gourami, corys, algae eaters, danios, Ameca splendens (livebearer), Heterandria formosa (livebearer), Endler's livebearers, bettas, fiddler crabs, red crabs, and shrimps of various kinds. Some other species I have tried have not done so well, perhaps because I keep the salt content quite high for the livebearers.
I enjoy watching the fish in my pond behave naturally. The fish swim wherever they wish and are not constantly bumping into the glass of a fish tank. I view them from above, just as if I was peering into a well stocked little pond in the tropics. Right now I’m happy with the livebearers but am thinking of introducing some not so friendly fish to help thin out the abundance of uncontrolled baby fish. I sometimes think of other possibilities for my pond – perhaps koi, or African cichlids, or even saltwater. These would of course require modifications to the low-tech nature of my present set-up. |
Looking
down into the pond. (If the pond looks different in some of these pictures, it it because
the photos were taken in different years. The plants change over time).
Emergent Hygrophila
corymbosa, in flower. Although it is often sold for aquarium use, this plant
obviously does not really want to spend its life underwater!