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.

Water balance and Vinyl Liners

Recently, one of my colleagues suggested I review an article about water chemistry and testing which focused on the effect of un-balanced pool water on vinyl liners. It concluded that balanced pool water has a major effect on the longevity of a vinyl liner in a swimming pool. I thought it important to pass on a summary of what was learned through the testing process.

We all know that water balance is important to the performance of the sanitising chemicals used in a pool, as well as for water clarity and comfort of the swimmers. However, water balance is equally as important for the life of your pool liner.

Using standard parameters of total alkalinity of 150ppm, calcium hardness at 100ppm and the starting concentration of cyanuric acid at 100ppm, a series of tests were conducted with different types of chlorine and PH levels ranging from 2.0 up to 10.0. Here is what was discovered…….

Samples with free chlorine at 1.5ppm where the PH was maintained between 7.0 and 7.5 (the Aust Std is 7.2 - 7.6) showed no adverse effects. The lower the PH dropped below 7.0, the greater the fading, wrinkling and loss of strength in the vinyl liner, plus it increased in weight (likely from water absorption which is what causes the wrinkling). As PH increased above 7.6 the vinyl lost weight and expanded. Samples with free chlorine at 20ppm where the PH was maintained between 7.0 and 7.5 showed colour change where white turned yellow and blue faded and became dull in colour. This high chlorine concentration caused wrinkling as well.

What this tells us is, it is important to maintain water balance to maximise the life of your pool liner. However, the study also revealed that even though the look of the liner changed with exposure to extremely bad chemical levels, the vinyl still remained functional as a pool liner!

Laser Measuring for Vinyl Liners

As a pioneer of Laser Measuring of Pools for Vinyl Liners, I thought I would share some guidelines on the type of measuring equipment available and where it is used. Firstly, assess what type of pool you want to measure to determine which device is required. Most pools are measured using a fibreglass tape measure which is okay for basic pools, but other devices are better when you have a lot of measurements or need to measure with more accuracy.

If you just want to use a laser device to measure A-B points and write them down, you can probably get a laser measuring device with +/- 2mm accuracy for around $200 from a trade tool outlet. This is a basic handheld device which will display the distance between two points but, in my view, is not all that useful when working with a lot of measurements. It doesn’t really save you any time because you still have to manually record each measurement, either on paper or on a computer.If you want to measure 2D style lined pools, capture the measurements on a device then download them to a PC or to liner order software. You can start with either a Leica brand “Disto” device which stores 1000 measurements to +/- 1mm accuracy, or a Hilti brand device. These handheld devices store the measurements on board so you can capture one or more pools of data and download them later onto your PC. These are a definite time-saver when working with a lot of measurements, but there are some limitations.

Let me explain.... One of the limitations of a handheld device is, exactly that, you hold it in your hand. This means your hand can move around and the laser point can easily stray off the desired target point in the pool. Ideally, you need a steady hand, or you may prefer to use a professional measuring instrument like a Total Workstation, as used by surveyors. These devices can be hired, but I recommend that you have sufficient training and experience before measuring a complex shaped pool for a vinyl liner.

For complex "3D" style pools, I suggest you engage an experienced surveyor to do the pool measuring for you. There are plenty of surveying companies around, but the key to a well-fitting liner is to ensure that the measured data points are located in the right place. This is something which requires the input from someone experienced in measuring pools for liners and cannot be left to the surveyor to decide by themselves. I recommend that you accompany the surveyor to site for at least the first ten pool measures to make sure they understand where you want the measurements taken. I suggest you mark the pool for the surveyor the first few times to help them understand where the seams on the pool liner will be located and therefore where the data points need to be. The pool liner seams are linked to the location of the data points so it is important the points are measured in the right spot, for smooth flowing lines through the pool. You can download a 3D laser markout sheet from ABGAL's web site which has more detailed information on what is required to measure these types of pools. ABGAL can also put you in contact with an experienced surveyor you can contract to measure complex 3D pools.

For information on handheld measuring devices please click here

Vinyl Liner Tile look

The largest pool liner market for Inground Swimming Pools is North America. The majority of the liners are manufactured with a "tile border" print wall giving a pool the look of a ceramic tile at the water line. The same style is quite common in Europe as well but not here in Australia. When I ponder this difference and having been involved in the Inground liner industry for over 30 years, I believe it has a lot to do with tradition and what patterns have been available in the market place.

In the past the Australia pool industry has had limited access to tile border PVC liners and therefore they are not common. The tile border patterns that were available in Australia looked "fake" and were quite boring as well, so not many pool owners chose them. In fact, for a while there were none available here due to a total lack of interest by pool owners.

Improvements in graphics with the use of computer technology has meant more design options and therefore much more realistic looking patterns. You now have a fabulous 3D effect in the design and so the opportunity for growth in this product is here in Australia with the availability of the pattern Reflections Tile from ABGAL. If you are looking for a traditional tile look in your pool with the low maintenance benefits of a vinyl liner, then try the Reflections Tile pattern from ABGAL. Whether for a new pool, or updating an old pool, this is great new look available now.

The Big Cover Up

Water is our most precious resource. Using a pool cover helps conserve water as it can almost eliminate evaporative water loss. I’ve noticed in the past year, many pool covers being sold online through eBay and other web pages. I guess pool owners are attracted to this method of purchase due to convenience and price! This makes me wonder, how important is product quality to pool owners these days? Perhaps it’s no longer the driving factor behind many peoples’ purchasing decisions?

You see, the quality of a bubble type pool cover is not easy to determine at all. Even for an expert, the formulation of the plastic cannot be confirmed without sending it to a laboratory for some very expensive and specialised tests. Now, thickness is a measure that is pretty straight forward to check, but in most cases you would need a measuring tool like a micrometer to be sure the thickness is what has been stated. The final factor is the reputation of the company you are buying from, and their stated product warranty (including the fine print!) and how easily you can make a claim. So how does a pool owner decide all this when buying online?

I believe a pool owner will “take a punt” in many cases when buying online, if the price looks low enough. But do they know what this could cost them in the long run? If the brand they choose is a brand they have seen in their local pool shop, then this makes it a little easier. They may feel reassured that if their local pool shop sells this brand of product then it’s probably a good quality product - and this is a fair assumption. But if they don’t know the origin of the blanket material (ie; not Australia) and they don’t know the brand or have no rapport with the company selling it, then the only reasoning they can use to purchase is price. The statistics on pool cover evaporation performance can look good no matter what the quality of the cover. For example, you could cover your pool with “Cling Wrap” and this would stop evaporation, just like it stops food drying out in the refrigerator! It would not last too long as a pool cover, but on paper, “Cling Wrap” would rate very well on evaporation performance.

I’ve been around a long time and there is a saying that goes back as far as I can remember which is “you only get what you pay for”. When you consider this, then buying an unknown brand of pool cover, online, from a company you don’t know, is very risky in my view. I know there are pool covers coming into Australia from overseas that are very low in price, but the quality of the plastic for our climate is not good enough to make them last a reasonable amount of time. “Seven months before it started to fall apart” was mentioned to me about a pool cover that was made in China. If you do the sums, a $200 pool cover that lasts less than a year, will cost you at least five times the price of an Australian made cover, over the time the locally made cover will last. Don’t get me wrong, there are plenty of great products made in China, but so long as they are branded and sold through known companies, you have some assurance the goods will perform. If not, you have a reputable avenue to make a warranty claim. So for my money, the choice is clear. Save money and buy an Australian made pool cover, one that has been formulated specifically for our harsh Australian climate, and is a well recognised brand. You’ll be glad you did your homework and be rewarded by years of hassle-free service.