search.noResults

search.searching

dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
Swimming Pool Scene INDUSTRY NEWS


Minimising Phosphate In Pools


Bacteria and algae flourish in water containing the key nutrient, phosphate. So minimising phosphate is a good thing. And it’s pretty straightforward.


The UK’s


authoritative guidance on swimming pools and spas


“Dedicated


solely to raising standards in swimming pool water treatment”


www.pwtag.org


Pool Water Treatment Advisory Group Email:


chair@pwtag.org ABOVE: Pwtag advises on ph correctants for swimming pools.


For years much mains water has contained phosphate at concentrations of 2-3mg/l, with no adverse effect on pool water. But without chlorine, eutrophication (excessive richness of nutrients, often due to run-off from the land) can begin with as little as 3mg/l.


Phosphates are also present in cleaning


materials, and de-scalers may contain phosphoric acid. It is for this reason that the use of general cleaning materials in the vicinity of the pool is not recommended. Some hypochlorite formulations also contain sodium hexametaphosphate to reduce scale precipitation, though its concentration appears to have minimal effect in encouraging algal and bacterial growth in pool water.


FREE CHLORINE Occasionally, if free chlorine concentrations cannot be maintained at a level sufficient to deal with algal growth, a phosphate remover may need to be considered. Flocculants containing lanthanum are effective at filtering out low levels of phosphate from pool water. Flocculation


54 Swimming Pool Scene INDUSTRY NEWS


Many water authorities introduce phosphates to mains water as it helps to protect old lead pipework from corrosion. And there is no official limit for its concentration in drinking water.


treatment containing a phosphate remover must continue until the algae are removed, even when the concentration is zero, because organic phosphate can re-enter the water by the disintegration (lysis) of bacteria and algae.


FALSE POSITIVES


Phosphate can easily be measured on site using comparator or photometer systems. Most kits can measure phosphate down to low levels and are therefore good, both for monitoring and for checking the performance of phosphate removers. But care should be taken to avoid false positives: many common pool-testing tablets contain phosphates, and over time these can build up on the side of the sample tube or vial.


Phosphate testing tablets are extremely sensitive and will detect any phosphate adhering to the tube sides and thus give a false reading.


So keep the phosphate testing equipment separate from other kits; thoroughly rinse the tubes immediately after use with deionised water (not tap water); from time to time rinse tubes with a weak acid solution (eg diluted vinegar) to remove any phosphate. And of course always follow the manufacturer’s testing procedures.


ABOVE: Measuring Phosphate levels can be carried out easily using a variety of testing equipment including the Lovibond® family of kits.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86  |  Page 87  |  Page 88  |  Page 89  |  Page 90  |  Page 91  |  Page 92