Old Bill wrote:
To answer your questions:
Yes we were getting a hard white calcaire build up. The sand in the filter was completely clogged up when we first bought the house and it required a lot of hydrochloric acid to loosen it.
The pool is tile/plaster finished.
As regards the filter, we have replaced the sand with small glass particles, which are supposed to be less vulnerable to being clogged up by calcaire.
Like Wendy, we have an infinity pool. I don't know what difference that makes to chemical usage.
I can't comment on the sand prior to you owning the house because who knows who looked after it.
Are there any actual figures for the hardness of your water and how is the water tested? A full set of water parameters would give a better view to your pool and as I posted before actually testing the well water also.
On glass filtration media, I will make it known that I am very familiar with glass as I am also a supplier for Dryden Aqua and their AFM glass. If your glass media isn't AFM then it will actually perform worse than sand.
I can say there is absolutely no truth that glass filter media is less vulnerable to calcaire. and a lot of the other claims from glass media are also false.
What I can say is adding a shed load of anti calcaire makes the pool water worse for two reasons.
1. Anti calcaire is a phosphated compound, phosphates are a food source for algae, it's like caffine to them.
2. Phosphates in the presence of calcaire in chlorinated water form a new compound calcium phosphate which will coat surfaces with a much harder compound than the calcaire itself.
Blame the ignorance on the swimming pool industry who know how to tap into owners bank balances. Anti calcaire doesn't and anti algae doesn't either both bad for pool owners but good for swimming pool companies.
Infinity pools tend to cause aeration of the water which under the presence of moderate to high alkalinity causes pH to rise and then a seesaw of chemicals can happen leading to greater expense.
IFTS report on filter media
Here
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