I bought a house with a pool last July (this is my first pool). It is in-ground gunite holding 22,500 gallons. I live in the New Orleans area. I do have a Taylor DPD test kit.
I am having lots of trouble keeping my levels balanced. Last summer, my main challenge was my cholorine level was too high and I could not get it down. I was not adding any granulated chlorine and my chlorinator was turned down as far as it would go. Finally, I added a chlorine neutralizer that got the level back in the proper range and it was fine through the fall and winter.
Now I am having the opposite issue-I can't keep the chlorine levels up. For the past month, I have shocked the pool every week with Power Powder Plus. Over the next several days, the chlorine level slowly drops and after a week is zero. The chrlorinator is turned up all the way and has 5 3" tablets loaded. The tabs are dissolving but I am not sure how quickly that should be happening. I am not adding any other chemicals except for PHOSfree. I have been in this same cycle for over a month. Water is clear but there are a few spots of yellow algae that keep growing on the walls and around the steps. We have not had any rain in a week, but before that it was raining a lot. During this past week without rain, this pattern did not change.
Here is my latest water analysis from Leslie's.
My phosphates have always been zero until the past 2 weeks. Yesterday, I added PhOSFree per the instructions from Leslie's to try and address the phosphate level.
I would appreciate guidance on how to solve my chlorine problem. I suspect it has something to do with my high CYA level. Any other guidance is greatly appreciated.