The Cairns Esplanade Lagoon

The Esplanade Lagoon was designed by Paul Stevenson & Associates NSW, with the plant built by Trisley Hydraulic Services then commissioned early 2003.

The design is a salt water, wet edge, free form, cement rendered trough style swimming lagoon with a surface area of 4,000 m2 and an overall volume of 3.8 mega litres, it is 135 meters in length and 60 meters at its widest point, the southern length of the lagoon has an artificial beach which extends into the water by about 2-3 meters

We have a turnover rate of approximately 4.5 - 5.0 hours / 230 litres per second.
We use four Chadson MHS- 7250 medium rate sand filters with a total surface area of 29 m2 and a Shunt valve Backwash system requiring approximately 20,000 litres each filter per flush.

It was part of our normal periodic maintenance schedule to inspect and if necessary service the filters by removing the top layer of sand and Appling a degreaser every 12 months however by end of summer 2005 / 2006 it became apparent this was no longer sufficient, our records had showed an increase in backwashing time and frequency also a reduction in flow rate and water clarity. This issue became a concern for our lifeguards on very busy days and especially evenings when it became difficult to see bathers when submerged in the deeper area of the pool.

It was then agreed that a filter media replacement would be made. Therefore quotes for standard filter media were received a plan and schedule for this task drafted, which was to take place before Christmas holidays 2006.

I'm pleased to mention that this plan changed after my visit to your display at the splash trade show on the gold coast last year were you explained the benefits and costs of your product, with this knowledge and after some more research I was confident if we used the Zelbrite media it would at best resolve a number of our previous issues.

Although the job was delayed till early 2007 it took two weeks to complete the task of replacing the media in all four filters [ two filters per / week]

I was surprised at the marked improvement of water clarity after only 24 hours of recommissioning the first two filters, once all four filters came online it became evident the clarity of the pool water was the best it had ever been, this firstly resulted to a number of positive comments from most of our regular bathers.

Our lifeguards were also very pleased as they found it easier to watch bathers when submerged. The night shift cleaners have also found it easier to vacuum the pool floor with cleaner, clearer water, less suspended particles giving them the ability to cover more surface area in one shift than before. We have also found the use of flocculants is no longer required although we still keep P.A.C in stock.

Our records also show we are more frequently achieving break point chlorination even after a moderate to busy day with water temps in the high twenties low thirties which has never occurred in the past.

So on behalf of Cairns City Council Esplanade Aquatics Staff I would like to thank you for all your help and assistance and would like to say your product has made a huge positive difference to the attractiveness and operation of our facility.

Kind Regards

Matt Roberts
AQUATIC SUPERVISOR
ESPLANADE LAGOON
CAIRNS CITY COUNCIL

Zelbrite - for Outstanding Swimming Pool Filtration