I just started a new 25K tiled pool. The pool has some kind of enclosure so it is pretty much protected from direct sunlight during the day. It has been open already a week, with FC around 1 and pH around 7.8, with only bleach added (no other chemical whatsoever). Water were sparkling clear. Now for the tricky part: yesterday evening FC was less than 1 so I decided to have little leeway and bump it up above 2. I added 2.4 ppm. Water are still good. After letting the pump run for an hour I also added about a quart HCL to lower pH to 7.6. The pump still running. A couple of hours later I went out to check on the pool. I almost blacked out. The pool was completely cloudy, with dense white powder throughout the water! I didn't know what it was, and I certainly did not suspect algae breakout. Instinctively I related this to my last action (pouring the acid). I forgot to mention TA and CH around 250 both. But if at all, acid dissolves this stuff and not precipitates it. So I was clueless. Decided to go to sleep and re-check in the morning. morning came, test results (k2006):
FC = 2.5
CC < 0.5
pH = 7.6
TA = 300
CH = 200
It didn't loose even 1 ppm overnight!
Now the water condition: most of the powdery white stuff sank to the bottom, I'd say something like 10% still remain suspended. Now it's evening, filter pump has been on all day. Filter is not clogged yet (return jets are still strong), and I think I noticed just a little tiny weak greenish taint on the white grout lines at the bottom of the deep end. Current conclusion: May be I succeeded to catch the algae in the beginning. So Why am I addressing this highly respected forum members? Here are my questions:
0. Could it be something not algae?
1. According to the CYA/FC tables I was well above the min FC for zero CYA. So why is the outbreak?
2. If somehow the table is wrong, what should be my current shock level? and my normal level?
3. Will the remaining white powder go away by itself? (of course pump running)
4. Is brushing the floor absolutely needed?
5. Is it safe to swim? Or at least only for me to enter for floor brushing?
Big Thanks to all replies, remarks and advice!