I have an open air pool in Spain and though I have had it for four years know almost nothing about pools - other than how to clean them.
The sand in my filter needs replacing, but I have put off doing it because I need to have some work done to replace tiles and a crack where the pool meets the patio.
Last week the chorline levels were low, even though there are still some tablets in the dispenser. So I put extra chorline in the pool.
This week the PH levels are very low. I will get some PH plus tomorrow, but in the meantime I would like to know what the effect is of low, or high, PH levels. I only have a simple test kit which shows four levels, it is on the lowest one.