I after completing our first SLAM on June 15 and getting everything back to normal, I've been careful to keep my target FC a little higher so as to avoid another SLAM. I've been monitoring the SWG closely, and with all this heat, it seemed to start not holding the FC as well so I began to get concerned. Right now I am running it at 100% for 12 hours and it's begun to not keep up with my target of 9 by the end of the day.
I thought I still had a CYA of 80 from when I slammed, but with splash out and an overflow from rain during the slam I found it to be only at 60 when I tested yesterday. I thought this might explain why I wasn't holding FC as well and why my SWG wasn't keeping up, but I don't want to add CYA until I know for sure I don't have another issue. I had to SLAM last time with a CYA of 80 and would prefer not to have to do that again!
I did an OCLT over the past two nights and each time had no CCs with an FC loss of 0.5, going from 8 to 7.5 the first night, and from 7.5 to 7 this morning. Water is crystal clear. I know with those criteria that I've "passed" the test, but when I finally passed the SLAM on the 15th, I had an overnight loss of 0 when my FC had been up at 33. So even this little bit of loss has me concerned.
Also, last night I tested at 9 pm and got an FC of 8. I decided to brush the whole pool, and then re-tested to be sure, and it had gone down to 7.5. I confirmed that number twice. So that adds to my concern.
Since I've been so careful with my FC levels I can't see how algae could be forming. The only thing I can think of is that I didn't know to wash all the pool toys and swim suits, so perhaps they have introduced it back into the pool?
What would you recommend I do? Thanks!