I've got a question regarding some CYA reading in my brother-in-laws pool. He's been having problems in his 21" round above ground pool with algae. He has a DE filter and uses pucks in a floater.
I did a complete set of tests using my <1 year old ps234 test kit. Within those results the main problem was his CYA, it had no reading of CYA. He stated that he added an unknown quantity of CYA in spring. In previous springs I have checked his water and his CYA always seems to go to zero (year after year).
I then told him to read the CYA instructions and add enough to raise the level to 30. He added some of the CYA that he had used earlier in the spring to his skimmer. After two days I measured the CYA and chlorine again...it was still clear as can be with the CYA test tube filled.
I have tested two other pools for CYA readings and both tests went fine and gave good readings. I'm at a loss.
Could it be possible that the container CYA goes bad? or could you buy some bad CYA?
I told him to pick up some new stabilizer and we would see where he is at in two days???????