Pond questions answered.

What should I do first?

Take some time to plan what you want to achieve. Planning your water features well will result in a pond or feature that is a pleasure rather than a chore. The main points to consider are:

Have easy access to power. Remember pumps & lights all require power: while it is possible to get solar powered pumps these are generally more expensive than mains powered equipment. Low voltage pumps are available if need be.

Avoid areas close to trees that shed a lot of leaves. Rotting leaf litter will pollute the pond, and also encourage algae growth. It is also important not to site your pond in an area that may be sprayed with insecticides or weed killers.

Plan to install the largest pond your budget and landscape will allow. Often a pond that looks huge when it is out of the ground, will look like a puddle when it is dug in to a large area. A larger pond will also be more stable from an ecological point of view. (they hold more fish too. )

If growing water lillies is your main reason for a pond then ensure that the pond will receive a good dose of sun every day, if you do not want to grow Lillies then a slightly more shaded area may be better.

Decide on the type of pond construction you want to use. Pond liners are far more flexible when creating just the right shape for an area, but a pond shell may suit your requirements just as well.

Lay the pond out in the area that you are planning. A garden hose or piece of rope is ideal for doing this. Lay the hose in the shape of the pond, and then leave it there for a couple of days to ensure that you are happy with the layout. It is far easier to change the shape of the rope or hose than to change the shape of a pond.

What are the choices in ponds?

The main choices when it comes to ponds are to use a flexible liner which will allow you to design your own pond and give you a great degree of creative control over your pond shape.

Polyethylene ponds (H.D.P.E.) are generally cheaper than pond liner and fibreglass ponds. These pond shells are sometimes referred to as "Rigid Liner", these ponds are tough and reasonably inexpensive. A large range of sizes and shapes are available.

The third option in pond choices is a fibreglass shell. These are the toughest of the lot, they are also costlier to produce than liner or Hdpe ponds. However there is an advantage in fibreglass ponds as they are often available in textured and coloured surfaces ie. "rock look". Fibreglass is also used to produce cascades, creek beds, feeder ponds etc. Don’t forget to have a look at the "Oz Rock" product line in store too as there are some great features which can be added to any pond.

Cement is sometimes used in pond construction, but while it is cheap, it is not a very good choice because of it’s effect on water quality, and because of difficulty in sealing it effectively.

Filtered or Non filtered?

If the pond is going to be used mainly as a fish pond then the answer should be "filtered". A pump & filter combination that is sized to the pond will help break down the fishes waste products and will help to reduce the amount of algae that grows in the pond. Water will generally be clearer in a pond that is filtered. For a Lilly pond or a pond that is just to be planted, a filter is not required and in some cases can actually be detrimental.

How do I know what pump / filter I need?

This is one area that gets a lot of people confused, and without the right advice you may end up very unhappy with the results you achieve. Firstly you need to know how much water the pond holds: there are three ways to find this out. First if it is a premoulded pond, then the volume of the pond is usually available from the supplier. If you are building your pond from scratch it can be worked out mathematically by measuring the length width and depth in metres and multiplying them together. i.e. 1.2m long 2.2m wide .6m deep becomes 1.2 x 2.2 x .6 = 1.584 cubic metres.

1 cubic metre = 1,000 litres so that pond holds 1,584 litres. As you can see the calculations are easy when a pond is a straightforward shape.(of course they rarely are….) In the case of most shaped or irregular ponds the calculations can get difficult so the another way of working out the volume is when the pond is filled for the first time, measure the flow from the garden hose before you begin filling. If the hose is flowing at say 30 litres per minute, and it takes 23 minutes to fill the pond to the top, then the pond holds 690 litres. Once you have this volume worked out, WRITE IT DOWN!!!

It is so easy to forget something like that, and yet the amount of work required to recalculate the volume can be a real problem. The volume of the pond is something you will need to know for various reasons (dechlorination, medication, pump selection etc.).

Filters for ponds come in many different forms from internal units that sit in the pond, external units that sit outside of the pond and return the water back to the pond by gravity and there are also sealed units which are available that can be used both internally or externally.

Pond filters are usually rated to a particular volume of pond and these ratings are printed on the literature that accompanies the unit.

Pump selection is an area that is not always as straight forward as filter selection.

There are two things that need to be taken into consideration when selecting a pond pump; the first is how much water flow do you need. This is a combination of all the total water movement that you want in the pond and will vary depending on the style of water features you want. For instance if filtration is your sole concern and you don’t want to run a fountain head or waterfall etc. then your pump size will only need to be large enough to flow the required amount through the filter.

More features will of course mean more water being used and as a guide the multi spire fountain jets use around 400 litres per hour and the bell type fountain heads will use around 600 l.p.h. (These are a guideline only) Waterfalls are a very variable thing, and depend on a lot of factors. To work out what sort of flow rate is going to be required to make your waterfall look good is easiest done when the waterfall has actually been constructed. To measure your required flow rate, place a garden hose at the top of the waterfall and then adjust the flow until you get your desired effect. Once you have the flow looking good then measure how long it takes to fill a bucket of a known volume & calculate the litres per hour from this. Now that we have all of the flows for the various features etc. we add them all together and it is generally a good idea to add around 10 – 15% on top of that total. (it is easy to turn a pump down, but when they are running flat out that’s it).

The second major consideration with pump selection is head height. This is a measure of how high the pump is able to lift water. Each different pump will have a maximum flow and a maximum head figure printed on it. These two figures are directly related. A pump will flow it’s rated maximum amount of water only when there is no resistance to the water flow.

Making a pump lift water or making it force water through pipes decreases the total amount of water the pump can move. At the pump’s maximum head height the pump will actually cease to pump any water at all. So to choose a suitable pump we need to look at the maximum height that the pump will need to lift water up, and also how far through pipes etc. it has to move water. (water moves more freely through larger diameter hoses than it does through narrow ones, and smooth pipes offer less resistance than corrugated or kinked ones. ) The right pump for the job is the one that will flow the required amount of water that you need, while still overcoming all of the things that are trying to slow the flow down.

We can assist you with pump selection, to help you on this if you find it confusing.

Is there a way to stop algae turning my pond green?

Keeping plenty of live plants in the pond, and not keeping huge numbers of fish in the pond will both help to keep algae growth down. It is important also to make sure you don’t feed the fish too much. Algae is a natural thing in a pond, and having a little growing on the walls of the pond should be seen as a healthy thing. However the bane of most pond keepers is the "Pea Soup Water" algae which can totally cloud out a pond. There is a device available called an UltraViolet clarifier which allows you to use a specific sort of light to kill this free floating algae. When matched against an appropriate pump & filter these units will guarantee clear water. For more information just ask us.