Pumps for U/V 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 this made them more effectively 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 U/V clarifiers 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 feasible 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 pumpwhere
water flows into the pool, to minimise the disturbance to the pool
environment. These are two considerations you will have to consider
compromising when combining filters and waterfalls. If you need a new pump, it will help your Aquatic retailer if you can be sure
of what you want you water garden pump to do. Assuming you will want a
submersible pump because they are the most efficient and cost effective for the
price, here are a number of factors you and he will have to consider. 1.The
cost arises before the pump is in place. Do you have power out to
the pool or water feature? Doing the job properly with armoured
cable and waterproof junction boxes can easily outstrip the mere
cost of the pump. Also do you have RCD trip switches installed to
isolate the pump from the domestic mains? 2. The above question
leads onto safety, even though all electrical connections must be up
to professional standards, many people with young children are still
frightened of putting a machine running of 240volts into water a
child might put its hands into. There is a huge range of low voltage
pumps that can produce quite adequate performance for most domestic
water gardens for very little extra cost and in total safety. You
just need to find somewhere to put the transformer. 3. What do you
want the pump to do? Will you want it to run a fountain, waterfall
and a
biological filter? A biological filter needs to be fed the
total volume of the pool every two hours. So you must know the
volume of your pool. A rough guide is adequate: (LENGTH x WIDTH x
DEPTH) in metres x 1000 = Volume of the pool in Litres The pump
should be capable if pumping half that figure to an appropriate
filter. If the pump is to run a fountain as well then you need
possibly 1000 litres an hour extra for that. Gushing frothy
fountains may need a lot more. Waterfalls need at least 120 litres
per hour for each centimetre width to the required head of the
waterfall. This translates to 60 gallons per hour per inch. 4. For
filter pumps. Is it capable of handling solids? A fine sponge
pre-filter may help protect delicate bearings but it doesnt allow
much muck to get through with an all too regular wash out. 5.For
filter pumps in particular, is it continuously rated? Does the
guarantee cover it for running non-stop. 6. Fountain pumps with
fine rose jets need a good pre-filter on the pump otherwise you are
forever cleaning them out. 7.
For
waterfall pumps and filter pumps, looking on the performance
table, is the volume of water you require to the height that your
filter and waterfall header pool sits well within the 40% -80% of it
maximum rated flow. 8. The costs of the pump can be easily
outstripped by the costs of running it. A good motor that is capable
of shifting 1000 litres and hour can be as little 15Watts. 9. Has
it got all the fittings you need in the box? If you need extra
fittings they can be quite expensive. 10. Is it easy to take apart
and put back together again for ease of maintenance on a cold
autumnal morning?
10 Considerations that effect your choice of pump
