I have had a problem this year maintaining any type of FC levels in my pool. I have shocked and overshocked my pool in the evening and by morning my FC levels are at 0. I also run the filter 24 hrs with 3 in tabs in the skimmer and still there is no FC readings. I have been using quite a bit of shock and tabs to no avail. I have not had an algae problem at all. The water has been cloudy at times but a flocculant has taken care of that. I have been to my local pool store and had my water tested and was told my nitrates are high. The have me shocking my pool quite a bit over the next few days with calcium hypo-chlorate. The have said this will destroy the nitrates. I have read on line that the only way to get rid of nitrates is to drain and re-fill. Also if the nitrates were high wouldn't I have an algae problem? I have an 27 foot above ground pool with a capacity of around 1,500 gallons my other important readings are;
I use a Taylor test kit for all my testing. my Total Chlorine and Combined Chlorine are also at 0.
Could nitrates be the cause of the chlorine demand, and if so how are they removed from the pool?
If nitrates are not my problem, What else is there? Any advice would be appreciated