We have a 23,000 gallon gunite pool. It is 12 years old. We live near Boston. The last three years we have been fighting a losing battle with the chlorine level. We only get a reading the day after weekly shocking. The last two years we started getting pink staining on the walls. We found out it was copper staining from the water. We treated that and still no chlorine.
Yesterday we had the water tested and they told us our nitrates are high. Sent us home with a box of shock, which we put in last night and today I tested and the chlorine is non-existent.
Any ideas what we should do to get the chlorine level to come up? Thanks.
Yesterday's numbers were:
Free chlorine 1 but when I test I get nothing.
Total Available Chlorine 1
CYA 60 (this was originally 90)
Total Dissolved Solids 1000