Ok, so now you have your pond installed everything’s looking fresh and new and sparkly and just wait for a few months when things start to green up a bit. It’s really beginning to look as if it’s been there forever and then something nasty happens…

The water starts to look somewhat cloudy and a bit too green. After that, you find this green stuff is everywhere like a mass of hair in your previously crystal-clear water feature.

This green stuff is called algae and it has been in existence on this particular planet for almost as long as water itself has. That’s about one billion years so I suppose it thinks it has a right to be here and indeed it has.

Without this remarkable plant there would be no life on Earth and therefore no you or I and therefore no pond. Your pond and its inhabitants need a certain amount of algae but that doesn’t mean that it has to over-run your aquatic work of art. There has to be a balance and balance is the operative word here.

As algae is formed in the presence of sunlight, to some extent the position of your pool is important. Exposure to sun from dawn to dusk will encourage the growth of the creeping green monster but if the pond is shaded most of the day by trees then you will have the other problem of leaves dropping into the water, causing some pollution as they rot on the bottom. If your pool is of the natural wildlife sort this not so much of an issue but your favourite, and expensive, Koi carp aren’t going to be very happy.

To counteract all this, the solution is to have a bit of movement in the water. In truth a pool of water will not go stagnant if there is as little as one drip per second, just enough to break the surface tension but far better and more attractive is to install either a fountain (the easiest solution) or a cascade (not quite so easy) or both.

The best way, in my opinion, is to build a rockery by the side of the pool and plant it up with the earth that you will have accumulated from the original excavation but this will be the icing on the cake. A note here about the excavated earth: You should keep any top-soil separate from sub-soil. Sub-soil is best kept for the use of aquatic plants.

You will also at this stage have to work out the plumbing for the water pump so that as much as the tubing can be hidden from view such as a pipe or conduit that can be buried or incorporated into the construction from pond to the top. This means that you can still access or remove the tube when necessary.

To construct your cascade you will have to obtain a quantity of broken masonry or hardcore (normally available from any sort on demolition site). This gives you a good solid foundation for your rocky waterfall. Just pile it up in its final resting place and then leave it for a couple of weeks to settle…

(Continued in part 2)