Okay. I thought I understood Pool School pretty well after spending countless hours on this forum last year reading and re-reading all the articles about water chemistry, balancing, SLAM and OCLT... Turns out I may not have understood everything...
I opened my pool May 1st. So much snow had fallen this winter, I didn't need to add any water! (as it was partly emptied at the end of the season last year). My test results for May 1st were:
I have to say I was a little surprised to have some FC in there after the winter, but the pool guys had put in a floating bottle of stuff and it contained Chlorine, so I figured it was from that. The water temperature was in the low 60s if not high 50s and the water was crystal clear! I expected a green mess, but it wasn't to be.
I then used the poolcalculator to get my numbers up to where they should be as I had used it many times last year, with great success. In the meantime, I FINALLY installed my 4 Deckjets. After 10 days, I tested the water (it was still very cold... water was still low 60s) All this time, I have a solar cover on the pool to warm it up and help keep FC in the pool...
Now, at this point, I discovered my pool was leaking some water. I originally thought it was the deckjets using some water as they drip a little, but after adding 4-5 inches of water per week since May 1st, I realized it wasn't the deckjets. The pool guys are coming soon to look at it, so it will be fixed, but it is messing my chemistry. I lose salt, CYA, FC, etc... But no matter, I try to keep the pool balanced regardless of the water adding.
I redo all the tests June 2nd to make sure my levels are holding, despite adding water...
FC 3.5 (a little low, but not too bad)
CYA 35 (uh-oh, too low indeed, time for some STAB before I lose all my FC and get some green!)
So here's when it gets interesting. The pool temp slowly creeps up to 80F and come June 7th, after about two weeks of me not doing anything to the pool, I remove the solar cover to find the bottom full of green patches. I'm thinking, no problem, I'll just SLAM. I've done it before and worked like a charm, so I'm not stressed. But then I start thinking... Why is it green? I do the full battery of tests... Here are the highlights...
When I opened the pool, I thought because the water was clear, I had some FC in there and the water was barely at 60F that there was NO WAY algea was creeping anywhere in the pool. So what happened here? Did I have invisible algea at the beginning of the season and when the pool temperature got up to "normal" it started blooming like crazy? Should I have SLAMmed the pool at the opening? Should I have done an OCLT at the opening to see it there was FC loss?
I'm still in the SLAM process now, which I started 2 days ago, but I have a feeling I'll pass OCLT tonight, but I'm still perplexed about how I got here...