Fact #3: Wrinkling of Liners in Indoor Heated Pools

The strangest phenomenon I’ve seen in my thirty-something years in the liner business is "wrinkling liner material caused by indoor heated pools". If you read my recent blog about chemical levels you would conclude that this problem relates specifically to imbalanced pool chemicals, but this is not the case from my experience.

It first started in the 80's when a customer contact us to say the pool liner in their 50 metre long pool, had grown about one whole metre in length. I almost didn't believe them, so I went to see it for myself.

When I inspected the liner, sure enough, there were wrinkles and folds of liner all over the floor of the pool. It looked like the reverse of a dry creek bed, instead of open cracks, these were folds of PVC in a random crazed pattern. After a lot of investigation by the fabric manufacturer, the conclusion was that this phenomenon was a reaction to a pool environment that was made up of the following factors:
· Indoor
· Heated
· Commercial use (like a training pool or public pool)

Another case which proved the validity of the study result to me, was a school pool in a cold climate. It was built as an outdoor pool and used for two years without any noticeable liner growth. Then, the school decided the pool would get more use if it was covered, so a new building was built over the top of it. It became an indoor heated pool and within one year, the liner had grown to have large wrinkles all over the floor.

How can this be? What happens is, under these conditions, the PVC absorbs water and therefore expands. The expansion becomes visible as wrinkles and there also appears to be deterioration in the strength and flexibility of the PVC; in severe cases I have seen cracking along the creases.

Different solutions were trialled like, maintaining a level of cyanuric acid (not normally needed for an indoor pool), using a lacquered fabric, using a printed fabric, yet nothing solved the problem and so it was concluded that unsupported PVC was not suitable for pools with these environmental conditions.

The fabric manufacturers’ no longer provide a warranty for their PVC when used for this application and so it used at the risk of the Purchaser.

There are plenty of domestic pools that are heated and located indoors which do not show any problems, but many of the commercial pools under these conditions will exhibit the considerable wrinkling caused by this phenomenon.

Fact #2: Pool covers save water - but how much?

One of the questions I am often asked is, “How much water does a pool cover save”? We all know that pool covers save water by virtually eliminating evaporation when they're on the pool, but how much evaporation does your pool have? It's a valid question and one that, in the past may have been quite subjective.

Now, you can look at statistical averages on the government weather bureau website to see 10 year averages of evaporation in your area, and then make some sort of calculation from there. However, the nationally endorsed Smart Approved Watermark website has developed a handy tool for pool owners to calculate how much water a cover will save. I’ve just tried it for my own pool and it showed evaporative water loss of over 73,000 litres per year. Isn’t that a staggering amount?

How much would your pool lose in a year? Click on the link and see for yourself, then tell your friends about it.

Go to and enter in your postcode and some details about the size of your pool and how often it is used. With a simple “click”, the magic number appears, taking all the necessary factors into consideration.

This means it's really easy to justify why all pool owners should use a pool cover and just how much precious water they will save. So, try it for yourself and spread the word, to see how much we can contribute to sustainable water usage for Australia’s future, today!

Fact #1: what you must know about Salt Chlorinators and pool covers

One of the best inventions for pool owners is the salt chlorinator. When these were invented, they reduced the weekly cost of adding chemicals to the pool and, most importantly, they were an automatic dosing system which meant less time spent maintaining the pool.

Fact #1: These units are not fully automatic. When running, they are constantly dosing your pool, so you still need to monitor the chlorine level yourself. Most pool owners think that these automatic chlorinators are "set and forget", but they are wrong! Checking the correct level of chlorine in the pool is critical for the health of your family.
It's also important for the life of pool accessories too. For example, a pool cover is so efficient at reducing the amount of chlorine needed, that the chlorine production on the chlorinator should be turned down by two thirds, so it is only producing around one third as much chlorine as when the pool is uncovered. If the chlorinator is not adjusted, the level of chlorine in the pool gradually increases to a point where it starts to attack the pool cover and pool cleaner and is not healthy for swimming.Obvious signs of an over-chlorinated pool are:

• Discolouration of the pool surface below the water level.


• The underside of the pool cover looks bleached.


• Pieces of the pool cover start to flake off and you find them in the pool skimmer.


• The automatic pool cleaner skirt and parts get sticky and discoloured.


• Pool accessories that are in the water start to perish (like the cord attached to a thermometer).

How can you fix this? Unfortunately, once a high chlorine level has damaged your pool cover or pool cleaner, the damage cannot be reversed. But, you can easily check the chlorine level yourself with a standard test kit — or even easier, by using testing (dip) strips, then adjust the chlorine output to suit.

The good news for the future is that self-adjusting, salt chlorinators are being developed and released into the swimming pool market. These innovations check the chlorine level at regular intervals and automatically adjust the chlorine output to maintain an ideal, continuous level. Look for these in your pool shop or online, if you want the convenience of not having to check chlorine levels yourself, and to avoid damage to your pool cover and pool cleaner.