Why & When Do I Need To Drain My Swimming Pool
by Knut Borgen
Is it true that there is a definite life expectancy time for water in a pool, even if rain and topping up due to evaporation takes place on a continuous basis.
Some people have told me max 5 years.Thanks for your question Knut
The life expectancy of pool water depends on a variety of factors:
Use of pool
Type of water (well, tap, pool water delivery)
Hardness of the water
Total Dissolved Solids (TDS)
How well you take care of the chemicals; i.e. excessive use of chlorine, muriatic acid, algaecides, etc...
So the real issue is when to drain and re-fill the pool. The measurement of TDS in pool water can be influenced by many factors; the chemicals we add to adjust the pH, chlorine, water hardness, alkalinity, dust, dirt, human waste, will increase the level.
The maximum acceptable level for TDS is 1,500ppm. If you allow the pool to get above this you run the risk of staining, the water might become cloudy, and it will reduce the effectiveness of the other chemicals.
You can have your pool water tested for TDS at a local pool store. If it's close to 1,500ppm, then it might be time for a drain and re-fill.
So TDS is the answer to your question. Drain and re-fill when the TDS reaches, or is close, to that level. You want to drain because the pool requires it, not because it's the last Saturday of September 2010.