CHOOSING PUMPS FOR MOVING WATER FEATURES

MOVING WATER FEATURES

For those of you that have been fortunate enough to visit the sensationally atmospheric water gardens of the General Life at the Alhambra Palace in Granada, southern Spain, you will appreciate the extra dimension moving Chenies and Brian Tom produced these clattering birds at Hampton Court many moons ago.water lends to a Garden even if it just gently trickling. The Alhambra was the summer residence of the Moorish Islamic sultans of Granada. The gardens, designed for contemplation in serenity, are in fact a series of 'patios' through which the flow of water leads you. Water is never concealed and never still in Islamic gardens, busily moving from its source to the exit of the garden, refreshing the atmosphere and murmuring through the vaulted interiors.

For the Moors, the moving water and the fountain jets all had their significance and symbolism in the meaning of life. In the west moving water was later used in entertainment as in awesome loud gushing fountains or waterfalls or used in a 'theatre' to drive automata - or literally moving water features, perhaps creating sound and power for whistling chirping robot birds in a metal tree: natural power for technological innovation. These started in Italy and the fashion moved to France and many of the English landed aristocracy copied some of the ideas in theri grand gardens in England. The power to all these aquatic fantasies was derived from the 'head' of a reservior or lake from land much higher up on the estate piped down to the fountain or waterfall.

These days we have made certain moves 'back to nature' and try to create something of the natural world in our back gardens now that we are so far from it in our day-to-day existence. Instead of employing the natural resources of the countryside (i.e. lakes and flowing streams) to power the technology that illustrates our fantasies, we create a fantasy of nature powered by our modern technology.

POWER TO OUR FANTASY- ELECTRICAL SUPPLY TO THE PUMPS FOR GARDEN PONDS AND WATER FEATURES

A professionally installed electrical supply to a large pond and fountain installation: Note the trip switches and timers. There is also an automatic lighting for the display as dusk approaches.Whether we have in mind to create a fountain, a waterfall, a stream or even to pump pond water to a biological filtration unit,  I would suggest that the first thing to consider is the electrical power to the site. This should have been considered and planned for This was the fountain feature: It required three pumps capable of supplying 8,000 gallons per hour at ground level.before any part of the water garden project was started. Therefore having reached the waterfall/fountain installation or creation stage, there should already be a 13 amp armoured cable running to the side of the pool. This will have its own RCD trip and be on a separate circuit to the household electricity. OK? Good, I just like to make sure.
You will have planned as if you were going to include all the possible accessories and features even if it hadn't crossed your mind to have a pool heater, a pump for an ‘inpool’ fountain, filter and filter pump, u/v lamp, waterfall, rockery lights, underwater lights and squirting frog (?).

PUMPS FOR FOUNTAINS or WATERFALLS?

Choose a pump for its (a) guarantee (Is it continuously rated? That is, does the guarantee cover it for use 24 hours a day 7 days a week? ).  
(b) Availability locally from a retailer you like and get on with.
(c) Its performance. This includes its suitability for its purpose. You dont want a pump that needs the protection of a thick foam pre-filter if it is meant to be supplying water to a filter system before it cascades down a stream or supply water full of organic debris to a biological filter.

One pump can run a filter system and a waterfall and they don’t need to be in series. They can have separate feeds from the same pump. One pump can also run a fountain and a waterfall but it cannot run a filter system as well, because for this you need the capability of shifting water with solids in it. If you want a finely jetted fountain or fountain ornament then to avoid unnecessary maintenance to the fountain (pricking detritus out of the jets) then you need a dense foam pre-filter on the pump and so a separate pump is advisable.
With regard to its performance curve as displayed on the side of the box, ignore the upper reaches of the line as the volume of water pumped drops off to nearly nothing. See what the performance is along the middle of the curve.
If you are aware of all your requirements before you buy, your local chummy aquatic dealer will be able to advise you on the options.

Old Oase Aquarius pump box: The performance curve top left, can mislead. The pump should not really be considered a viable if a performance above beyond the midpoint of the line is required. If the claim is that the pump has a head water at a 'max' of 2metres, there is hardly anything reaching this height unless there is a particular point made as to how much is delivered to that height.

The Nautilus range of Oase pumps are especially economical to run.: Note the wattage, combine that with the guarantee of up to 5years and you have a pump that is very good value for money. This is decidedly a fountain pump.

Laguna Powerjet Free Flo SB1500 Fountain & Waterfall Pump performance table: Although this table looks very simple, it is more obvious that at the maximum head you will get nothing for your money. It also tells you the maximum flow and the maximum size of pond that it would be suitable for running a waterfall or biological filter for.

The Hozelock Cascade 1000 performance panel keeps you guessing.: Although this panel maintains the Keep-It-Simple philosophy, there is too little said to make the performance properly comparible with other makes of pump.

FOR WATERFALLS.

Allow roughly 60 gallons per inch width of sill to the height at which the water supply enters the waterfall system.: On this waterfall there is a stream running to it from a further 3ft (less than a metre) higher. The waterfall is roughly 15inches wide and 2ft high, therefore I needed to find a pump that would supply at least 900 gallons to a height (head) of 5ft.When it comes to estimating what you want in terms of gallons or litres required for a waterfall you must take first of all the height of the waterfall at the outlet of the hose.  Normally this will pour straight into a header pool that will even out the flow of the water from the hose. Most manufactures will give performance diagrams or tables on the sides of their boxes or in their catalogues and these are often designed so that you find it difficult to relate these figures to any competing manufacturer’s pumps but are easy to compare with pumps within that manufacturers range.

Allow 50/60 gallons per hour/ 300 litres per inch, 100 litres per cm, width of sill at the lip of the waterfall. If the pump is underpowered for the width of waterfall you had in mind you can stretch it by breaking up the 'mirror' of the flow and having an undulated sill along its width.
Too powerful a waterfall can have an undesirable effect on the plants, so keep the maximum turnover at a lot less than the volume of the pool per hour.

This also goes for FOUNTAINs, lilies cannot abide being anywhere near splashing water so leave plenty of room for both.

PUMPS FOR FOUNTAINS

For small pools with tiny waterfalls or just simple fountain effects there are excellent 24volt submersible pumps on the market that are perfectly adequate for a small waterfall or fountain, but are hard pushed to provide for both.  A good visible fountain that is a pyramid of water roughly a metre high might come from a pump spraying 450 litres per hour (90gallons per hour). This might be the maximum performance of the pump or a significant proportion of it.

If you want the pump to run a WATERFALL AND A FOUNTAIN....

The larger the pump the less significance the effect the fountain on the pump performance will be, but it is a constant to bear in mind.
Don’t get too ambitious with the proposed height of your fountain. Allow at least the height of the fountain again before you reach the side of the pool to prevent the spray blowing out of the pool. Fairly wind resistant jets of waterFoam jets: they are stable in windy condtions and they oxygenate the water efficiently, but need a powerful pump to be effective. come with the gushing style of ‘foam fountain’. These make good aerators for the pool but require a proportionately powerful pump to make them effective.         

If you are running the fountain and waterfall off the same pump, estmate that the pump's performance at the waterfall will be reduced by at least 30% and considerably more if the pump delivers less than 1500 litres per hour to a 1 metre head.
Many pumps come with the fittings for a fountain and a 'T' piece hose connection for a waterfall often each outlet with its own regulator. So bearing this in mind, go for a little more performance than you think you need, because you can always restrict flow but you can never boost it (although the old style of direct drive pumps are less tolerant of too much restriction.) Also debris collecting in the pre-filter will soon damp down the performance.     
When it comes to plumbing and positioning the pump, remember again the flora and fauna of the pool would prefer as little disturbance as possible from moving water. Therefore site the pump as near as possible to the fountain ornament or waterfall and raised from the bottom of the pool in order to avoid as much turmoil as possible. This also reduces the pipe work and in turn the friction loss that professional pump suppliers regard as most important. For every foot of pipework, every fitting, bend or hosetail you are reducing your pump's performance by huge amounts. This also means you must fit the widest possible hose that the pump will take.
If you are running a spray fountain directly from the pump rather than to an ornament, then the position of the pump is dictated by where you want the fountain i.e. sitting on a plinth raised off from the bottom of the pool in a clear area of water at least one and a half times the height of the fountain away from the side of the pool.
Having said all this, if you are contemplating installing a BIOLOGICAL FILTER into your pool....

Pumps for BIOLOGICAL FILTERS

The squashed armadillo style of pump cage of the Oase Aquamax is a perfect shape for a filter pump.: It manages to draw towards it significant amounts of debris and takes a very long time to get clogged up even in the worst of conditions.The pump wants to be circulating the water through the filter from the opposite side of the pool.

The pump must be capable of taking up a certain amount of solid material that is it must not have a dense sponge pre-filter on the inlet. As for performance, a pump and a filter must be able to process the total volume of the poolThe Oase Aquamax using its dual inlet facility with a 'satellite pod' taking water from a remote part of the pond.: Oase give you the option of taking water from two places at once. in two hours. Therefore in a pool of 1000 gallons or 4500 litres, the pump should be capable of delivering to the filter 500 gallons or 2250 litres at the height above the pool surface that it happens to be set at.
Most manufacturers are at pains to point out is that the figures they provide only hold if the maximum bore pipe-work that it is feasible to use is used and that fittings are kept down to a minimum. They can also affect the longevity of the pump, particularly on the more old fashioned designs. Just the length of hose itself can reduce the performance of some pump designs quite radically. Estimate to lose between 60 and 100 gallons per hour for every 10 foot length of hose (in litres per hour, between 273 and 455litres) even on the horizontal.

Ensure the pump cable is long enough to reach from its position in the pond to the power supply junction box. All modern new pumps should be fitted with a minimum of 10metres of cable, which is adequate for most installations. If the pump needs to be situated in some vast lake then genuinely waterproof cable connectors can be obtained from Electrical wholesalers at no little expense.

Fountain water features can recquire a relatively powerful pump to supply quite a modest flow.: Its due to the restriction of the copper pipe running through the ornament. Speak to the sculptor or manufacturer on the pump that they would recommend.

Blagdon Hydratech Torrent Pump HTT5500: Specifically designed for pond filtration, if debris clogs it up, it spins in reverse, thereby clearing the blockage. Hence the pristine impellor even after running in a virtual quagmire.

Pressure filters like this Oase Filtoclear reduce the pump performance by as much as 40%

PUMPS FOR ULTRA VIOLET CLARIFIERS AND CLARIFIERS FOR FILTERS

There is no doubt that filters seem doubly effective if they are working in conjunction with an Ultra Violet Clarifier or UVC. By passing the pool water through a container lit with a fairly low dose of ultra violet light, it was found that unwanted algae that made the water a green colour, clumped together and made them more easily filtered out of the system. UVCs need to be chosen to be compatible with the filter and the pump with different sizes and wattage of lamp available for different flow rates. It seemed to me that you could allow one watt of lamp power to treat roughly one hundred gallons of pool water, with a throughput of 50 gallons per hour through the lamp. But that may be simplifying things too much when you have sophisticated designs like the Hozelock Vorton and the Bioforce filtrations units on the market.  Your retailer will advise you on the right clarifier for the flow rate from the pump.
The UVC must sit in processing the water from the pump before it gets to the filter. Some people like to use the outlet from the filter as the supply for a waterfall. This is ok as long as the waterfall is allowed to run 24 hours a day, since the biological filter needs a constant supply of fresh oxygenated water. Filters are also more effective if the water is pumped from the far side of the pool, so there is a true circulation of the pool water. If the waterfall is very forceful, install the pump close to the where water flows into the pool, to minimise the disturbance to the pool environment. These are two considerations to bear in mind when combining filters and waterfalls.