Building a Garden Pond is something that you should not take on lightly. In this article, we explain exactly what is involved in building a substantial concrete block pond which is then sealed with a special type of waterproof varnish. The longevity of this type of pond is beyond doubt provided it is constructed properly, whereas any pond built using a butyl rubber or polythene liner is only a relatively short time. Liners are also prone to leakage, caused through ageing, root penetration or even accidental damage by the owner or their pets.
Once the site has been earmarked, the size of the finished pond needs to be ascertained. The advice most often given to newcomers is to build the pond as big as your budget will allow. This is the best advice and one which we support. The difference in both cost and effort involved in building a larger rather than small pond is disproportionate to the difference in size. The pond size we originally planned was 10ft x 10ft x 42" deep without bottom drains and built as part of our replacement patio.
The next item that must be ascertained before cutting the first sod, is what type and size of filtration system you are going to provide in order to give your fish a healthy environment. If your intention is to have Koi in your pond, you need to pay special attention to the filtration requirements and probably include bottom drains, as these beautiful fish have very demanding water quality. As I wanted community pond fish rather than koi carp, there was no need to build-in bottom drainage although I would use a gravity settlement system prior to filtration. The reason that you need to decide on your filtration requirements at the onset, is so that they can be built-in to the overall plan as good filtration can often take up a considerable space.
Our advice would be to build your own filtration unit as part of the Garden Pond, and avoid the "off-the-shelf" type of filter as these are generally a compromise and are also difficult to hide in the normal garden. This will not only save you a considerable sum of money, but also give you a filter of a specification more suited to your pond. There is nothing complicated about building your own filtration unit - anyone who is d-i-y capable and happy with both plumbing and electrical work can easily do it. A separate page will discuss this job in more detail.