We are often asked why has my swimming pool’s bubble cover started to degrade? The usual pattern is that you find little bits of white plastic floating in your pool water. You wonder where they have come from and eventually find that they are from the underside of your pool cover. The bottom of the bubble has degraded and fallen off.
A typical failure looks something like the image below.
The material becomes brittle and the cover literally falls apart. This type of failure happens when either the cover has reached the end of its useful lifespan or something has happened to shorten its lifetime.
The plastic that the cover is made from contains antioxidants and chemicals to protect it from breakdown by UV light from the sun. These chemicals don’t last forever and as the cover ages so these chemicals get used up. The either the oxidisers in the pool water will break the plastic down or the UV light from the sun will. Or a combination of both.
This process should happen after about 6 years but sometimes it happens after only a few years. Why is this? In almost every case it is because of chemical attack on the plastic from the pool water. Excess chlorine in the pool water, whether for a prolonged period or intermittent periods, will attack the stabilisers and and deplete them in advance of their usual lifespan. Once the UV stabiliser is depleted by the chlorine the sunlight will finish off the job of breaking down the plastic.
What can I do to prevent this happening?
Many pool owners say that they do have too much chlorine in the pool and this may be so for most of the time but if you shock dose the pool and put the cover on straight away you will harm the cover. Sometimes you get high levels of chlorine under the cover but don’t realise you have done it.
Pool covers come with solar protection sheets to cover them when they are off the pool. These should always be used.
Roll the cover off the pool so that the bubbles are down. That way the sun can’t shine on them.
Are some covers better than others?
Yes. The higher the grade of material used the longer the life span of the cover. Three grades are available 400, 500 and 600 micron. This refers to the thickness of the material, the thicker the better.
The new Geobubble Swimming Pool Covers will last much longer not only because they are made from 500 and 600 grade but the additives are better and the shape of the bubble is such that it does not have weak corners that are always the first to fail.
So to summarise.
- Don’t let the cover come in to contact with high chlorine levels when shocking
- Make sure you don’t accidentally over chlorinate and if you do take the cover off
- Roll it up with the bubbles down
- Put the solar protection sheet on