Short summary: New house, first time pool owner. 25,000 gallon in-ground pool. When I opened the cover last month, it was green and full of leaves. Weeks of many shockings, DE backwashing, more shocking, etc, and the pool is clear, but I'm still struggling with chlorine.
I hadn't been checking the numbers daily. (beginners mistake), but I went to the pool store last week where I was told I had 0 chlorine and a ph of 7.0. I picked up a k-2006 test kit, added soda ash and almost immediately got an algae bloom.
More shocking later, and the water is clear. But now, no matter how much I shock, I get numbers similar to this:
FC - 0.6
When I went the pool store, they said my chlorine was fine, but I do not believe them unless the high CC can somehow interfere with the FC test. I did the test, my chemical engineer wife did the test, and we still get low chlorine and high CC every 24 hours after shocking.
BUT: I used a regular DPD test that the previous owners left behind, and the "FC Red" was higher than 3.0. What do I believe?
Calculators say I need to add 4100 oz of bleach to the pool. That seems completely insane to me. I don't even know how I would buy that without triggering some sort of bomb threat.
As a side note, it seemed to take 3x the amount of soda ash it should have to raise my pH, it that provides a clue to anything.
Any ideas? I suspect part of the problem is that I need to scrub the sides of my pool a little better.