It has been an education

[dcarroll001]

Thanks for putting this site up. Between this site and some YouTube videos, I feel like I understand what is going on. I put in a 20k gallon vinyl above-ground pool last year, with a deep end. I had no problems until about the 1-year anniversary in May, when algae sprung up suddenly and wouldn't go away. We don't really close pools here in Texas, but we do get a lot of rain in the month of May (and usually no rain after June 1). I determined the CYA was too high (100+) after using hockey pucks last year, so did a partial drain and refill last week, and got it down to 45. After two shocks this week, the pool is clear. Today a little algae popped up at one sunny end of the pool when FC dropped to 5, though I think that may be a circulation problem. Ph of 7.5, with TA initially around 125 (after the refill, city water is a tad high on TA), but I've lowered it to 110. I'll probably try to knock that down again with some acid, though some sources tell me that that is within the acceptable range (pool math tells me to get it to 50-90, while others say 80-120). Hayward pump and sand filter, I've put in a special return nozzle that I saw on one post here to try to get better mixing of the water. Now I am measuring FC loss and raise rates at different times of the day. It's been hot, so I've been losing about 5 or 6 ppm on some days. That translates into a bottle of chlorine a day, though I'm not sure yet how consistent the loss rates are.

 

[mknauss]

Welcome to the forum!
Read the SLAM Process. Sounds like you need to follow it.
I suggest you read ABC's of Pool Water Chemistry