Soft Water in swimming pools

[kammalla]

According to South West Water, the fresh water that is used to top up our swimming pool is 'moderately soft'. What? I understand that water type will affect the type of chemicals used in the pool but what I'm struggling to get my head around is what it means to a pool operator?? (What I'm trying to learn for).

[Buenchico]

Your water has between 20 and 40 parts per million of calcium:
http://www.southwestw...df/2/3/Hard_Water.pdf

Most sources seem to suggest that such a level is lower than required, as the pool materials might start to dissolve into the water. e.g. see here:
http://www.swimmingpo....co.uk/spcblog/?p=256
and here:
http://www.poolandspa...serates.html#hardness

Chris

[jomifl]

If you are using calcium hypochlorite as a long term bactericide then as the chlorine esapes to the atmosphere the the calcium hydroxide remaining will combine with carbon dioxide in the atmosphere to form calcium carbonate(chalk) and eventually precipitate thus making the water cloudy. If you have a low level of hardness it will take longer for this to happen. Where I live we have quite soft water and it took about 2 years for my neighbours pool to go cloudy. It should be easy to clear with hydrochloric acid.

[madijay]

Soft water basically is the process of removing calcium and other minerals to "soften" the water or make less "hard".
partially softening typical “hard” water is OK but fully softening is not a good idea.
see here for more information:
http://www.aurorapoolsandspas.com