How to Build a Fish Pond

Every great garden has a water feature. It’s the finishing touch that charms the ears even as it soothes the eyes.

Installing a pond is not difficult and does not have to be expensive. Look around the internet and you’ll find many pond-and-fountain kits just right for the patio. Just add water, plug in the pump and let it go. If you move in a couple years, you can even take the pond with you.

But with a bit more investment and space, you can build a permanent pond that will delight you for years. You’ll find yourself looking for any excuse to serve cocktails within earshot of the pond or curl up with a good novel nearby.

People sometimes think that a fish pond is a lot of work. It doesn’t need to be. Once installed, a pond needs only a little maintenance. Scoop out fallen leaves and petals from nearby trees and clean out any gunk that gets in the filter – that’s about all that is usually needed.

In general there are two approaches to building a pond in Houston. The in-ground pond, which is usually more naturalistic in style, uses a black rubbery liner. You dig a hole the shape and depth you want your pond to be, line it with the liner and then conceal the edges with stones and plants or decking.

Or you can build a raised pond, typically more formal and made of concrete block with brick or stone facing. That’s what we did earlier this year, and I want to share the process with you.

Planning for the pond started in late spring as we began year three of our total home and garden renovation. Contractors had left a muddy and rubble-strewn mess in the back. Here’s a photo taken from the balcony.

Two years ago we had purchased old wrought iron fencing for the front garden and several pallets of Pennsylvania bluestone from Historic Houston Salvage Warehouse, which had recovered both from a River Oaks mansion that had been demolished. Both had been sitting and waiting to be installed. Then, earlier this year, a friend who owns a vacant lot in River Oaks told us we could have the pile of old bricks sitting there if we arranged to have them removed. Three days later the bricks were neatly arranged in our yard.

This beautiful old mossy brick was exactly the element that our garden had been waiting for. It was time to get started.

During the construction of our garage and repair of our house we had used a concrete/brick crew that we liked very much. They showed up when they said they would. They were tidy. They stayed on budget. And, what I liked best, the crew included two women. So we called them to help us with the garden and pond project. It took a while to get on their calendar, but once they got to work they cleared the back garden quickly and set up forms for the concrete base.

Then they began to cut and install the bluestone and use the recycled brick to build the patio edging. Note how the pond is actually made of concrete blocks; the brick is just the facing. Inside the pond, where the water would be, we skimmed the blocks with mortar and then painted them with a thick rubbery black paint specially formulated for fish ponds. It’s fish- and plant-friendly and seals the pond so that water doesn’t weep out. It also smoothes the interior of the pond somewhat so that the fish don’t scrape themselves on the rough concrete.

Once the hardscape construction was finished, my husband Cameron ran PVC conduit from the garage along the back of the deck and to the side of the pond where he installed an electrical outlet. The big day was when he hung what we call “the spitter fish” that we found a couple years ago at The Guild Shop. He connected flexible tubing from the little pump sitting on the bottom of the pond, through a hole in the side of the pond (above water level), up around the back and down through the spitter fish’s mouth so that we had a gurgling flow of water.

We left the water to age and aerate for about 10 days in order for the COH’s chemicals to gas off. Yes, you can use dechlorinator to do that almost instantly. But I prefer the natural aging system. We were lucky we had a good rain, too, so that would help to make the pond water gentle on the new fish.

Then two of the kids and I headed out to Katy to Nelson’s Water Gardens and Nursery where we strolled the beautiful grounds. If you’re a gardener, this is a magical place that will spark throbbing plant lust. It’s full of pots, plants, mobiles, and fish large and small, not to mention all the equipment you’d ever need to build a pond or fountain.

Our pond is fairly small at just 200 gallons, so we couldn’t go too crazy with the plants. (Here’s how to figure out how many gallons of water are in your pond.)

I spotted owner Rolf Nelson, whom I had interviewed for The Houston Post about a million years ago, and he took a break from grooming lilies to help us pick out a couple water plants of the right scale. We settled on a miniature rose-colored water lily to sit on the bottom of our pond and an arrowhead Sagittarius, which is a wetlands plant. The arrowhead needs shallow water, so it sits on a stack of bricks in our pond that puts the top of its pot just six inches or so below the surface of the water.

As the nursery guys carefully wrapped up the two plants for the trip back to Houston, we headed to the outdoor tanks where young goldfish and baby koi are kept. One of the things I like most about Nelson’s is that the fish wrangler takes great care to scoop up the exact and particular fish you point out. He’s very gentle, and the fish don’t seem to mind cradling in his hand.

We selected seven fantail goldfish, all of them gold or white or gold and white so that they would contrast with the inky blackness of our pond. I think our chances are excellent that we have some of each gender. Maybe we’ll have some babies next year.

Nelson’s also sells koi, and I have had koi in the past. But they would get too large for our small pond. Plus, koi can be kind of messy, stirring up silt as they poke around in the plants looking for something to eat. Goldfish are well mannered and very friendly. They are also surprisingly hardy.

We headed home and floated the inflated bag of goldfish in the pond water. The usual rule of thumb is to allow about 20 minutes so that the temperature of the water inside the bag becomes the same as your pond.

Meanwhile, we unwrapped the two plants and set them in the pond. The only care they will need until springtime fertilization is to have old leaves snipped off. I usually do that with my thumbnail.

Soon it was time to un-do the rubberband on the plastic bag of fish and release them into the pond. This step always makes me nervous; I worry that one of the fish will become trapped in the collapsing plastic bag as the air and water rush out, though that has never actually happened on my watch. Nevertheless, I asked our son Sam to set the fish free.

Several weeks later, all seven fish are healthy and growing like the proverbial weeds. Morning and evening I head a few steps out to the back garden with a glass jar containing baby goldfish pellets. I gentle knock the jar against the brick of the pond a few times – a dinner bell, if you will – and all seven fish zoom to the surface, greedy to eat. A couple tiny pinches is all it takes.

Do you have a fish pond in your garden? We’d love to see your photos! Email them or post them on our Facebook page.