I am new here. I took care of my pool myself for 5 years. 6 months ago I turned it over to a pool company for chemicals only. I don't know if it is related, but I just noticed an overall brownish stain on my plaster. I took my water to have it tested. Results are:
I have not had algae problems. I use city water. Pool is starting its 6th season this summer. Filter and Pump are 2 years old. Polaris and polaris pump are original. No heater.
What should my course of action be?