Note: this was originally published as an article on kuro5hin. You can read the original article (and reader comments) here.

Water, water everywhere...


I wanted a pond. Our back yard doesn't really lend itself well to pond construction - it's too sloped and would have required some serious earth-moving. I'm too lazy for that, and we're not planning on staying in this house for much longer anyway. A container pond seemed to be the answer - small, easy to maintain, and most of all, cheap. I could have plants, fish and a certain Zen beauty on our back deck for next to nothing.

I happened to have a suitable container, so I set out to build a container pond capable of supporting various plants and a few fish for under US$30. I'm just about finished, and will likely come in under budget. This short article will explain how I did it. There are vast resources online dedicated to water gardening, and I'll include some links at the end. I realize I'm only scratching the surface on some of these topics, but I want to show how someone can get a small container pond up and running in a hurry for a minimal investment.

All you really need is:
  1. A container
  2. Water
  3. Plants - in addition to looking nice, they clean and oxygenate the water.
  4. Fish - they control insects and look nice

Container


You can use just about anything you want for a container. Several websites out there show how to create container ponds out of old whiskey barrels. These work pretty well, and the consensus is that they look nice, too. Depending on the condition of the barrel, a liner may be required, though in fairness, the internet-container-pond community seems sort of split on the issue. If the barrel can't be made watertight, you're going to need a liner of some kind.

Some stores sell pre-formed rigid liners made specifically for small water gardens. You can also purchase flexible pond liner. But this is about doing it all on the cheap, and just about any watertight container can be used: buckets, washtub, bathtub, or animal water trough. As long as it's clean, watertight and non-toxic.

I didn't have any barrels, but did have an old plastic planter rattling around the shed. I dug it out, and cleaned it out - scrubbing it with a bleach solution and rinsing it well. I also had to plug a hole in the bottom of it. I cut a small square of plastic from its drain pan, glued it on the bottom of the pot, then filled it in from the top with ordinary tub-and-bath silicone. I let it sit for a day to cure.

As this was all stuff I had laying around the house, I've gotten this far without spending any money. Figure out where you want to put the container. Most water plants need around 6 hours of sunlight per day. I found a spot on our deck that got the required sun and was close to an electrical outlet should I decide to add a pump/aerator at a later date. Remember that water has weight - I calculated the total capacity of my container at around 45 gallons, which means the thing weighs about 375 lbs.

I broke down and bought some long concrete blocks that raise the container off the wooden deck about 3 inches and spread the weight across one of the deck joists. I filled the container with water and was pleased to see that my patch and my deck were holding together. My deck, for those of you who are curious, actually sits on the ground, so a collapse isn't going to be a particularly dangerous situation. Exercise caution, all the same.


Water


Clean water is essential to a healthy pond. Tap water contains chemicals which keep the water clean, but which need to be removed before plants and fish are added. If chlorine is present in your water, simply letting the water sit out for a few days will let it 'dissolve' out of the water. If your water is treated with chloramine, you may need to use a chemical to treat the water. Your local pond stores can tell you what steps, if any, are required for cleaning your water. If there aren't any pond stores in your area, check with reputable aquarium stores.

I bought some chemical water treatment, just to be safe, but later found out that our water has chlorine, which would have evaporated out on its own. Rats! I'd spent money unnecessarily. Plan on adding water occasionally to replace what's evaporated. It's possible that your water will cloud up in a hurry because of an algae bloom. Don't panic - things usually level out in a few weeks. Having the right mix of plants can help keep algae at a minimum without the need for chemicals or mechanical filtration.


Plants


Plants are vital to the pond ecosystem. They aid in water filtration, oxygenate the water, provide shelter and food for aquatic life, and look nice. There are three different categories of pond plant, and representatives from each are desirable for a well-balanced pond. Like other plants, aquatic plants need occasional care - pruning and thinning, and may benefit from occasional fertilization. I plan to start out simple, so my criteria for choosing plants was cost, ease of care and hardiness (ie, how likely am I to kill this thing?).

Submerged

Submerged plants are just that - nearly all of the entire plant is underwater, either rooted in some planting medium such as aquatic planting soil or pea gravel, or free floating. Submerged plants oxygenate the water and help control algae. I decided on Anacharis (also called elodea). It's cheap, and usually readily available. It also grows really, really fast. If your local pond store is out of stock (as mine was), try your local aquarium shop.

Helpful hint: when it's time to submerge potted plants, cover the top of the soil in a thin (1-deep) layer of pea gravel. It'll keep most of the potting soil from billowing out into your pond as you sink it.
  

Floating

Floating plants filter water and provide shade for your fish. One of the most common floating plants is the water hyacinth. It looks nice, and cleans the water like a mad bastard. It is also one of the most noxious, fast-growing weeds known to man. If you live in an area where water hyacinths can overwinter, plant it with caution, and don't let it escape into local waterways. You'd think this would go without saying, but water hyacinths have spread in exactly that way - pond owner is thinning out his plants, and chucks the extras into a local pond, lake or stream. Likewise, if you live in an area where water hyacinths grow wild, you may be able to get some for free from your local ditch.

Marginal

Marginal plants typically grow on the edges of ponds. They're usually situated in containers within the ponds so that the top couple of inches are exposed, with the remainder of the pot underwater. I decided against marginal plants, but some you might consider aquatic cannas, hardy water lillies, or even carniverous bog plants like pitcher plants or venus flytraps. You'll need to provide a submerged shelf of some kind, for holding the containers up, as well as the correct sort of potting soil.

Home Depot sells a vinyl-covered wire basket with hooks that's used for hanging flower pots on deck rails - they work very well for holding marginal plants at about the right depth. You can also up-end terra cotta pots for raising submerged plants up to the their ideal depth.

For my container pond, I've decided on water hyacinths, anacharis, and a variegated reed for vertical interest. Whatever you decide, make sure to check its winter-hardiness for your area. Certain tropical water plants may need to be brought indoors. Your local nursery can help you choose winter-hardy specimens. My initial budget prevented me from considering things like water lillies and lotuses, but I've since added a winter-hardy lily. The pond store lady knew me from church and threw in a water lettuce plant for free.

Fish


Fish are fun, and add a little excitement to the pond. They also help keep the insects at bay.  My pond has been set up for about a month, and I haven't seen a single mosquito larva in the water.

Common pond fish: comet goldfish, mosquito fish (Gambusia affinis) and koi. Koi are better off in larger ponds, but at least one barrel-pond-keeper has had decent luck with Koi. I like Koi, but truthfully didn't want to spend the money, and feel that they need more space than I could provide. Maybe on the next pond. Mosquito fish are sometimes given away free by municipalities as part of their mosquito abatement programs. They seem almost engineered to eat mosquito larvae, but are also very prolific breeders.

My local pond store was out of mosquito fish, so I bought a trio of comets. Our kids like them, they're easy to spot in the water, and they're cheap to replace. If the pond is balanced out, the fish shouldn't require feeding. If you must feed, feed sparingly - only what the fish can eat in a five minute period. Excess food falls to the bottom, promotes bacterial growth and fouls the water.

Fishkeeping is a discipline unto itself. I've kept aquaria before, so it's familiar territory for me. In a nutshell: don't overfeed or overstock. Watch the water temperature. If the fish are gasping for breath at the surface, you need to areate the water with an airstone or small waterfall. Start simple. One rule of thumb is that 1 inch of fish for every 5 gallons of water obviates the need for mechanical filtration. Stay on the conservative side, and realize that some fish will grow to fit the size container they're put in. A reputable pond or aquarium store with knowledgeable staff will prove invaluable. Failing that, avail yourself of the internet communities, or seek out other pond people in your local area.

If it gets cold enough in your area for your pond to freeze, you may need to consider bringing the fish inside for the winter. If the pond is deep enough, the fish may survive the winter providing that the pond doesn't freeze solid, and that any crust of ice on the surface is opened to allow gasses to escape from the water. DO NOT SMACK THE ICE TO BREAK IT. The shock can kill the fish. You don't need to feed them, either. Fish go into a hibernation state when the water temperature is low and will not eat. The food will fall to the bottom and foul the water. If you're in doubt about your region, the size of your pond or your fish's ability to weather the weather, contact a local expert at a pond store or perhaps at a local extension office. If there's no one around to consult, make plans to bring them inside just to be on the safe side.

Conclusion


That's about it.

These are the hard and fast rules. The rest is basically up to you. I find water gardens very relaxing, enjoy the activity that the fish provide and believe that they'll provide a fantastic educational opportunity for our kids. And while the rest of the outdoor landscaping wilts under the remaining summer drought, I've still got a little bucket of paradise in one corner or the patio.


Pictures

A couple of pictures showing the pond and two of the fish. The last shot shows nearly all of the plants present. Starting from the twelve o'clock position, you can see the marginal reed in its own pot, floating water hyanciths, a hard water lily and a light-green water lettuce sort of floating in the middle. Through one of the open areas, you can barely make out some of the submerged anacharis.  Things are a little clearer in the full-sized view.


container pond, side view two of the comets, under some hyacinths top view, showing plants



Initial investment:
Concrete blocks and water treatment, $6
Water hyacinths, 5 for $10
Comet goldfish, 3 @ $1 ea.
Anacharis, 3 for $6
Total: $23

Subsequent purchases
Hardy water lily, $8
Dwarf variegated reed, $8
Pots, soil, supplies, $10
Pea gravel, $2
Golden Snails, $5

Update:
Since I originally wrote this, we've gone through a couple of winters. This should have occurred to me earlier, but an elevated container of water freezes a heck of lot faster than something in the ground might. Also - I'd put the kibosh on snails. They'll eat your plants alive, and you'll end up picking some up on any plants you bring home anyway.

Useful Links

Make A Big Splash With A Tiny Water Garden
Eric's Half-Whiskey-Barrel Pond Page
The Half-Barrel Pond Page
Fish In A Barrel
Robyn's Pond Page
USDA hardiness zones
European hardiness zones