I am building in my back garden, and can't decide what would be better preformed liner or just loose pond liner. Any ideas?
preform, by all means. they usuallu include different depth shelves allowing for different kinds of plants. doing that with a flexible liner is tough.
I would say that would have to do with how large of pond you want. If it's just something small, I would go with a preformed. If you want it bigger, go with a liner. The most important thing is to have the correct amount of plants, shade, and good filter,especially if you are going to add fish. Don't forget that Koi do not belong in a small pond as the can get well over 2 feet long in a short period of time and all fish produce a large amount of waste.
The custom built pre-formed ones are fine as long as you make sure that you get the hole perfectly dug to the exact shape of the form. If you don't, it leaves little gaps/holes in the pond where it's not touching the earth. Any weight, such as the pressure of the water or a human stepping on those gaps, could cause the form to crack, thus causing a leak. Concrete is fine, but it has to be cured, sealed and rinsed very well to prevent any lime from leeching into the water. This can throw the ph way out of balance, cause poor water quality which could kill the fish. The liner is the cheapest and the easiest. It will form fit to any shape you dig in the earth. The only worry you have with liners is to get rid of all rocks, which is easy because they're easy to see and also because you put a good layer of sand over the dirt. It's not toxic to the fish and it's less expensive and less work and worry than concrete. Oh, a hole can be punched in liners also, but it takes a pretty good force to punch through that thick rubber. When I had to get into my pond to clean it or anything, I just went in barefoot. No sharp tools, no sharp shoes, no worries. My pond was 120 gallons, so, yours is about the same size. You fish will be so happy with their new house! Congratulations to you for taking such good care of your fish!
