With a TDS meter...your local pool supply store can do this for you.
You will have to drain some or all of the water depending on how much TDS you need to remove.
Drain and refill all or a portion of the total volume of water.
This depends on how long the water has been in the pool and how much fresh water has been added etc More useful information may be gained from following the link below.What is the Fuss Over Total Dissolved Solids?
Water is changed when calcium hardness, cyanuric acid, or total dissolved solids become too high. In Las Vegas we recommend every two years due to high calcium hardness.
By measuring the length and breadth of the pool we can measure its area.
'Swimming Pool', sometimes shortened to 'Pool'.
pool
What are swimming pool "Coopers"
it depends on which swimming pool
You have to know what you are doing. The addition of muriatic acid lowers the pH and total alkalinity in swimming pools.
less than 1000ppm
Water too old, that's a new one, Here in the great white north, our swimming pool time is limited to about three months in the summer. We start prepping pools when the last freeze has passed. Typically what greets the average pool owner here after pulling back the winter cover looks more like a bog than a crystal clear chlorine oasis. Suspended or dissolved solids as discussed in the Discussion area exposition will only become worse by reducing the water level, and generally return to pre-drain levels with refilling. Your solution is a good filter. Large solids can be skimmed out. Dissolved solids require more than the average pool filter. Consider a centrifugal prefilter, replacing your sand/medium filter, and installing a cartridge post-filter.