Building Your Own Large Fish Pond

There’s nothing quite like a water feature in a garden. The sound of water, the appearance of it, the reflectins and the wildlife it attracts all make the effort worthwhile. And there’s nothing quite as a lovely as a great big fish pond, complete with a collection of healthy, beautiful fish. Maybe it’s because humans spent aeons on the seashores of ancient Africa surviving on seafoods. Who knows why we love water so much, but we do. It seems to be in our DNA. If you’d like to build a large fish pond in your garden, here’s some handy information.

large fishpond

How to Build a Pond – Large Pond Liners Rule!

How to make a pond? You could dig a hole, line it with natural clay and hope for the best. You could buy one of those inflexible, solid plastic preformed ponds or a preformed pond liner that you have to dig a special-shaped hole for. But to be honest, your best and easiest bet is to use a sheet-style large pond liner, ideally the best quality butile you can afford with at least a ten year guarantee. You don’t need to dig a hole in a specified shape or size, just go with the flow and dig the way the lie of the land dictates.

It’s always a good idea to create a pond with both shallow and deep parts. If any small mammals fall in the pond they’ll be able to climb out to safety – hedgehogs in particular tend to drown in garden ponds, which is such a shame when their numbers are already dwindling fast.

Once you’ve dug your hole, it makes sense to extend the life of your pond liner to the max. If you lay it on a surface with sharp edges or bits of stone poking through the soil, the weight of the water will probably make tiny holes in the liner, a disaster in the making. We tend to line the hole with at least a couple of inches of fine-grained sand, which we then cover with layers of old duvets, blankets, sheets, towels… basically any fabrics you can find. Bin bags also work well. Then, when you finally lay the pond liner in the hole, there’s very little chance of anything sharp being left behind to cause holes and leaks.

Edging Your Pond – Rocks or Grass?

One of the nicest ponds we ever built has a simple, plain grass edge. We dug it in the centre of a lawn, fitted the liner, then simply laid a good six inch layer of soil over the edges of the liner then turfed over it so the grass met the water’s edge. Beautiful. You can also go the traditional route and place heavy ornamental rocks, stones, pebbles and even gravel to hide the liner’s edge.

Dealing With Leaks Further Down the Line

Pond liner repair is something you might want to think about, and there are kits to do exactly that. But in our experience locating the site of a leak is a really big challenge, a whole lot easier said than done unless it’s a big, obvious hole. It’s far better to do the due diligence thing and make the best possible job of ensuring a leak-free lining in the first place.

One of our fish ponds sprang a leak we coudn’t identify. We eventually gave up and re-planted around the edge to cover the bare part of the liner. The pond endled up less deep but still funtioned well until, 15 years down the line, it sprang a leak deeper under the water. We toyed with emptying it and adding a new liner on top of the old one, which turned out to be an excellent solution despite being a stinky, messy and long job. We know people who have transformed their badly-leaky pond into a bog garden instead!

More Pond Supplies for Your New Water Feature

Fish pond kits are handy. But it might prove better to buy bits and bobs as and when you need them, unless you can find a kit offering exactly what you need to the exact right specifications.

We find anti-algae products very useful, especially in the first few days of a new pond. It can take as little as seven days for wildlife to discover your new fish pond and make it their own. But most ponds go through a pea-soup stage in the first few days, where the water goes the most amazing vivid green thanks to algae. A dose of the good stuff gets rid of it in no time. Hair weed is a frequent issue, which you can either hook out with a net or kill off with various proprietary chemical products. Grass carp are brilliant at eating duckweed, probably the most effective way to get rid of the stuff, and they don’t require a filter.

If you’re keeping ornamental fish like fancy koi you will definitely need a filter. But your average garden-wildlife pond will thrive without one.