Archive for March, 2011

Pond Filters – Which One Is Right For You?

pond filterIf you want to keep your pond clean and healthy, then a pond filter is the answer. There are a lot of different types from which to choose and choosing the right one all depends on what you expect out of your filter. Firstly, a word of warning. Pond fountains often state that they have a built in filter. This usually comprises a small piece of sponge. Its purpose is to stop small bits of debris entering the fountain head and blocking it up. That is all it does. It will not keep your pond clean and will not eliminate green water. This requires a different type of filter. Let’s look at what is available and what would be the best buy for your pond and your budget.

A pond filter usually comprises either a submerged all in one pump and filter, an external pressure filter or a ‘black box’ external filter.

See Pond Filters for sale at

Hozelock Easy Clear2

Hozelock Easy Clear2

For smaller garden ponds, a submerged in pond pump and filter will suffice. These all in one pump, filter and Ultra Violet combination units are ideal for the smaller garden pond or water features as they are so easy to install and maintain and easily hidden. The Hozelock EasyClear and Oase Filtral are good examples of this type of filter which contain a pump, UVC and filter in one unit.

For many larger garden ponds, the traditional ‘black box’ filter is ideal. The black box is just that, a box containing filter medium, an inlet hose into which water is drawn by a pond pump and an outlet hose through which water is passed back into the pond. They will also often contain a UVC to help clear green water.

Ecopower 4500 Combi Filter

Ecopower 4500 Combi Filter

They are usually sited slightly away from the pond so that they can be hidden behind plants or a low wall. They can often be partially buried into the ground. To do this, look for models with a top inlet and outlet. Water is pumped in at one end from a pump situated on the floor of the pond. It then passes through a UVC (ultra violet clarifier) which causes green algae to clump together into larger lumps. From there it passes via a spray bar over the first filter medium, often coarse sponge, which traps these green clumps of algae and any other water-borne sediment. Often 3 different grades of sponge are used to trap different sized particles.

The water will then pass through another chamber containing large pieces of filter medium or bio media such as flocor, in which friendly bacteria will consume harmful bacteria and pollutants, further clarifying the water. It then passes out through the outlet hose and back to the pond. In some more advanced versions, water will pass through brushes before the foam to remove larger particles.

Oase Filtoclear

Oase Filtoclear

Pressurised filters are a lot smaller and so are extremely popular for small to medium sized ponds. As they can be partially buried, they are a lot easier to hide than traditional box filters. Not only can they be situated almost anywhere around your pond, they can also be easily covered up with plants or a cover making them easily disguised. Pressurised pond filters usually have a built in UVC (ultra violet clarifier) which helps to eliminate green water. Pressure filters are also easy to maintain, many having a built in self-cleaning device. The Oase Filtoclear is a good example.

Koi ponds will usually require something a little more elaborate than this. These will be dealt with in a separate article.

For more advice and some great deals on pond filters, you may like to see some of the following web sites which we recommend for quality as well as price.



Choosing a Pond Liner

Pond Liner

A Butyl Liner

There would be nothing more disheartening than to spend a lot of time, effort and money on planning and building a new pond only to look out one morning to find your pond liner had let you down and your pond empty with dead fish at the bottom. This could happen and is the reason to choose the right pond liner at the outset and to install it correctly.

It may seem that there is a huge array of types of pond liners but in actual fact they only fall into a few categories and choosing the right one for you is quite easy. Get it right now and your pond will last you for years, quite likely even your lifetime.

The most common types of liner are PVC, LDPE and Rubber.

PVC liners are best suited to the smaller, ornamental garden pond. They should also be fitted over a pond liner underlay for maximum safety. I would also lay a bed of sand under any liner to protect from sharp stones.

LDPE (Low Density Polyethylene). This is an ultra-tight weave of tough fibres which are then sandwiched between two layers of rot and UV resistant laminated coating. The result of this is that these liners are tough and astrong; however they still remain supple and flexible enough to be moved easily into position when building your pond.

Rubber (often referred to as butyl or EPDM) pond liners are excellent for any pond installations as butyl easily moulds itself to the pond’s contours. It is very flexible and elastic, although its thickness makes it quite heavy. It is also UV stable and so will not deteriorate when exposed to sunshine. Butyl is usually .75mm in thickness. EPDM tends to be a little thicker for the same resilience value, often 1mm, although it is said to be more resilient to puncturing, but not as resilient as butyl to impact. EDPM is also a little cheaper than butyl.

The choice therefore comes down to the size of the pond you are building and of course that dreaded word; budget. Butyl will be the most expensive option, but for a larger project, you will be getting a liner to possibly last a lifetime. All liners should come with a guarantee and this will give you a good idea of how good that liner is. It is better to cut down on the size of the project than the quality of your liner.

For more advice and some great deals on pond liners, you may like to see some of the following web sites which we recommend for quality as well as price.

Choosing a Pond Pump

Pond PumpPond pumps are used alongside water features such as fountains and waterfalls as well as filters in order to recirculate the water. This helps to keep the water well oxygenated and when used with a filter, can help to keep it clear and healthy. There are two types of pond pump; surface and submersible . Surface pumps run above ground and are usually housed whereas submersible pumps run under the water. There is a large selection of pumps available but they mainly fall into two main categories; pumps to run water features such as fountains or waterfalls and pump to shift solid waste material into a filtration system. Of course, the outlet from a filter can be returned to the pond via a waterfall.

One thing to bear in mind though. It takes a considerable amount of pressure to pump water uphill. If you intend to run a waterfall, then think carefully about the height to which you want to pump water before choosing a pump. The more water you want to pass through the waterfall, and the higher you want to make the feature, the bigger the pump you will need.

For waterfalls, you will  need to know the width of the lip feeding back into the pond. A waterfall will need at least 250 litres per hour for every inch of waterfall lip width and so if you  are considering a 6″ waterfall lip, you would need to pump 6 x 250 = 1500 litres per hour.

Most pumps today state in their specifications the amount of water they can pump at a certain head height or head rate. This is the height above water to which they can pass water at the given flow rate. So if you know that you want to pass 1500 litres an hour through a waterfall which is situated at 2 feet above the level of your pond, then you need to look for a pump which states that it can pump at least 1500 litres an hour at 2 feet head height.

For a fountain you will need to choose a pump with a fountain head long enough to reach above the surface of the water. These pumps usually have an integral “filter” which stops any debris being drawn up into the fountain head and blocking the spray nozzles. Don’t be fooled into thinking that these sponge filters will clear your water. They are there only to stop blockages and will need clearing out often.

For a filtration system, then you need a large pump capable of handling solids. These pumps usually state that they can pass through solids of up to a certain size such as 5 mm and this debris gets passed right through to your filter system.

For a more detailed discussion on pond pumps and advice on choosing the best pump for your pond, see our web site page on choosing a pond pump.

To see some of the pond pumps available now, see our pond pump shop page.