Water Gardens Gazette number 316

When a person builds a pond it is to achieve the vision of
crystal clear water. The vision normally includes a pond full
of colourful fish and attractive aquatic plants.

Often the reality of a pond is something quite different ...
a green smelly hole in the ground. This need not be the case.

This article identifies the really important factors that
will result in a beautiful pond, something to be proud of and
which the family can enjoy. Something to add value to your home
and lifestyle.

Before you dig the hole do understand that if you intend to
keep fish then a biofilter must be installed. A biofilter
can be a fairly simple box shaped container with a suitable
biomedia inside it onto which bacteria can accumulate so that
they can do the job of purifying the pond water day in and day
out.

The job of the biofilter is to purify the water first and
foremost. Fish excrete ammonia which if allowed to build up
results in the fish poisoning themselves ..... remember those
goldfish in the bowl which lasted about a week ... they died
because there was no biofilter to purify the water. The fish
poisoned themselves to death in simple terms.

The biofilter's secondary job is to remove solids. Many
people believe its job is to remove solids as its most
important function ... not so.

 1. Avoiding Problems and Hassles
When you have finished reading this article and if you are still not sure or would like some re-assurance ask someone who can provide the information and will give you sensible advice.
If the advice is sound and makes sense and can be backed up by example or published information then it is probably good advice. However if something does not make good sense to you; if it is too general, like a biofilter must be 20% of the pond's volume for example, then maybe seek further advice and certainly probe the advice given. A bad installation is expensive to fix.

2. Some general tips to start off with

Problems can show themselves in many forms but the most obvious and frequently encountered is the dirty water pond.
Unless you are prepared to install a biological filter I would strongly advise you to reconsider your intention to build a pond. Without a biofilter you will be almost certainly be disappointed with your pond and it will be a source of annoyance rather than a pleasure. I promise you that you will install one sooner or later. Do yourself a very big favour and do it in the beginning. Pond keeping is about enjoyment. It is not about hassles and disappointments.

4. The pond pump is the heart of a pond system

Do not buy a pump until you know how to select the right
one. The chances are you will get poor advice from many
retailers and be sold a pump which is totally unsatisfactory
because some retailers themselves do not fully understand what they are selling. The cheapest pump to buy is often the most expensive to run especially with regard to larger capacity pumps and running costs can be very high.
Every unit of electricity consumed by your pump will cost at
least 25 cents if you live in South Africa.

Pumps should have at least a 2 years guarantee and for ponds must have 10 metre cable lengths and 3-core cable at that. It is illegal in South Africa to sell a pump with less than 10 metres of 3 core cable for outdoor application.

If you want a fountain effect in your pond choose a pump that comes with a fountain attachment. They can be expensive to buy later. Such a fountain can only run well if the pump has a strainer device. This is normally a special
open-celled plastic foam on the suction side of the pump. It
prevents particles of dirt from blocking the fountain nozzles.
It also is used to protect the pump's impellor.

If you do not want a fountain in your pond then save
yourself a tremendous amount of maintenance effort by buying a pump with an impeller that can run without the need for a strainer on the pump inlet. These pumps are sometimes called vortex pumps indicating the impeller can handle solids.

5. The only guaranteed way to avoid green water

Do seriously consider spending a bit extra on an Ultra
Violet clarifier (UV for short). This keeps your pond from
going green in summer. It will make a dramatic difference to
your enjoyment of your pond and is the secret to crystal clear water. I am tempted to say that if you do not do this at the time of installing your pond you will wish you had done within 6 months.

6. Not too many fish

Do not overstock the pond with fish. For the gardener with a
small pond of say 1,000 litres or less goldfish are ideal. They
are hardier than koi, eat less than koi and so grow more
slowly. They do not destroy plants as many koi will do. However do not let me put you off keeping koi. These fish really are wonderful and beautiful fish. Put less rather than more fish in your pond but we recognise this is difficult advice to follow especially when you have a beautiful, crystal clear pond and you have managed to breed some of your own fish.

7. Make it easy to maintain your filter, pump and UV

Do make access to the filter and UV easy. Use good quality
pipe fittings. These will cost more but will repay the
investment many times over when the time comes to maintain the filter or UV. When selecting hose keep the diameter as large as possible and minimise the hose length. Avoid piping that kinks and avoid bends and sharp corners because these can seriously effect the output from a pump. The ideal size pipe for most garden ponds of the sort we are discussing (up to about 5,000 litres ... say 3m x 2.5m 0.6 metre deep) is 25 mm internal diameter.

8. A waterfall is a source of oxygen for a pond

Unless you really enjoy landscaping and digging buy
yourself a waterfall or stream made from glass fibre with a
rocklike appearance. These are so realistic these days it makes no sense at all to me to go out and buy rocks and then engineer them into a waterfall using liners or concrete. A waterfall is a great way to introduce oxygen to the water which helps in the overall good health of the pond.

9. Very important ... feed high quality fish food

Do buy high quality food. It probably costs a bit more per
packet but repays itself handsomely in water quality
improvement and reduced filter maintenance. Your fish will also benefit far more from this food and odds are at the end of the year you will have spent less. If there is no information on the packet indicating contents and analysis DO NOT buy it. Aim for a minimum of 35% protein and ash content less than 8%. Water or moisture content should be 10% maximum.

10 Aquatic plants make a pond special

If you intend to put water plants in your pond and I highly
recommend you do this then plant them in pots and in good
quality soil without fertilisers and maybe a bit of bone-meal.
Be aware that water lilies do not like turbulent water or
splashing. Oxygenator plants are very good for any pond. Koi generally like to eat plants so protect them by using gravel on top of the of the soil after planting in the container.

Don't forget ...