So, you’re ready to build a new pond, or expand the one in place already. One of the first questions that you need to figure out is how you’re going to line the pond (assuming that you’re not just going to dig a big hole, fill it with water, and hope that it somehow works – not a path I recommend highly anymore). Broken down to it’s simplest form, you’ve got three basic choices: Treated Concrete, Preformed Pond, and Flexible Liner. Each of these is the right choice for some ponds, and each has its advantages and disadvantages. Here are a few of the key points.
Concrete used to be the standard for pond building. It has mostly fallen out of favor these days, though, as preformed and flexible liners have gotten better and better (especially with regards to durability). A concrete pond requires the most work to install, by a great deal. It’s hard, backbreaking work that requires more than a little bit of skill to do well. It’s also generally the most expensive liner type. It also must be carefully and thoroughly treated to make sure that the concrete doesn’t leech any lime from leeching into the water, which can cause catastrophic swings in pH. It is certainly not an undertaking to take on lightly.
However, a well-built concrete pond can last for generations. The durability of concrete is still unmatched by other pond liners. For a professionally-installed pond where budget is less of an issue, or for very large ponds, concrete can still be a great choice. Just be sure that you choose a pond builder who has significant experience with building concrete ponds. As the pond building industry has exploded and concrete ponds have become rarer, not many pond builders really have experience working with the material. In most areas you can still find pond building firms that specialize in concrete ponds (usually older companies), but they generally don’t come cheap.
Preformed ponds are the other end of the spectrum from concrete ponds. Preformed ponds are far less expensive and definitely the easiest to install. You don’t even have to dig your hole to precisely the shape of the pond; you just have to dig a hole big enough to get the pond in, then backfill the hole as you add water to the pond. You know that your pond will be exactly the shape that you’re looking at when you buy the liner. However, there are significant limitations on what preformed ponds will be available, both in size and shape. It can be difficult to find precisely the right preformed liner for your needs and desires, and there is definitely an upper limit to how big preformed ponds can realistically be. Most first-time pond owners end up going with a preformed pond, and it’s a superb foray into the world of pond ownership. In my experience, though, many, if not most, pond owners end up wanting to go bigger and more elaborate with their ponds eventually, and go with a flexible liner their second time out. I certainly did, though for the second pond that I built I actually left the preformed pond in place and turned it into an upper chamber for a two-part pond, which kept us happy for years.
Flexible liners are my favorite type of pond liner by far. They’re relatively easy to install (though not as idiot-proof as a preformed pond), and they’re definitely the cheapest pond lining solution you’ll find out there. Advances in materials have yielded pond liners that are far more durable than you might expect, and they can be expected to stand the test of time. Flexible liners give you the most options, are easy to maintain, and good for both fish and bog ponds. So long as you account for water flow, pump size, and filtration needs, you can really let your imagination run wild with a flexible liner pond. They’re also arguably the easiest to adjust and change over time, if you wish. You can build a pond with just about any edging, too, and have it look great, while preformed and concrete ponds tend to be a little more limited in this regard. While they’re definitely more work than preformed ponds (though far less than concrete ponds), I find that the investment of time and energy is more than made up for in the joy you’ll find in getting exactly the pond that you want.