Testing for Phosphate Made Easy

The increase of Phosphate levels in the UK water system spells bad news for pool owners The UK has been quite strict on water purity for over 120 years and continues to set new standards in the market. Throughout this history, products have evolved to address new guidelines, legislation and best practice in the industry. Now and again things do change in the industry which renders additional tests more important both for the commercial pool maintenance manager and the domestic pool tester. Allen Wilson (FISPE) spoke out about the new EC Directive 80/778/EEC on the contents of lead in drinking water and how water utility companies are adding phosphates to water to inhibit resultant corrosion. It has been found that the addition of Phosphate to a potable water supply can significantly reduce lead and copper levels - helping us to meet these EU directives on drinking water standards.

Testing for Phosphate Made Easy

But there has to be a “But”
The immediate effect of this is already being noticed in swimming pools with increased outbreaks of algae – phosphates are, basically, fertilizers.

Increased Phosphate Levels
Encourage algal growth
Affect pool appearance
Impact pool performance

Increased algae require increased Chlorine dosage which incurs increased costs so testing for Phosphate is becoming more and more important. Since additional Phosphates in pool water have an effect on both the pool appearance and performance, it is essential that the levels are controlled and kept very low. Measuring Phosphate levels can be carried out easily using Phosphate tablets and then reading the results either on a comparator system or a photometer.

Now for the next “But”
Care has to be taken, however, as a number of tablets used for other tests such as DPD No1 also contain Phosphates. Using a tube that has been used for Chlorine testing, therefore, can result in a false positive reading, as the tablets pick up the residual Phosphate that has adhered to the tube.

Testing for Phosphate Made Easy
Always use a set of tubes specific for the test
Rinse tubes immediately after use with deionised water (some tap water contains Phosphates) and drain dry
Occasionally rinse tubes with a weak acid (vinegar) to remove deposits

N.B. The information contained in this entry is provided by the above supplier, and does not necessarily reflect the views and opinions of the publisher