I have a 20' AGP which holds roughly 8,600 gal. I'm using chlorine. This is my first season with this pool and using chlorine after having to replace a similar pool which I was using a SWG which rusted out the support beams after three seasons of use.
Cut to the chase: I am attempting to use the "slam" method for the first time.
I got algae from letting my FAC run too low. Yesterday morning water was cloudy and I vacuumed up some green residue on the bottom. I added a 121 oz jug of chlorine and one lb of cal hypo.
By afternoon water was clear with some greyish-looking residue on bottom. Apparently all the chlorine was consumed during the day by the bright sunshine and algae as I tested the water and my K-2006 kit showed the FAC was close to zero, TAC was zero, CH was 260, CYA was 40, TA was 70 and PH was 7.2. Water was clear with a small amount of residue on bottom. I let a pool store test my water and they came up with roughly the same numbers.
I upped the FAC to 16 IAW the chart I saw on this site. There was still about an hour of sunlight left in the day when I added the chlorine.
This morning, approx. 0800, after sun had been up roughly an hour, I tested some of the parameters again. My FC was 14, CC was 0.2 and ph was 7.5. Water was crystal clear with a lot of dead algae (I assume) on the bottom.
Questions: Do I up the FAC to 16 this morning or monitor it during the day and up it later? I guess I am really asking if I need to have it close to 16 this evening so that I can see if it "holds" within 1 ppm overnight or if I can do the test with it a little less than 16 if that's where it is by late afternoon?
Should I vacuum up the residue on the bottom or just sweep it and assume the high level of chlorine will take care of it? If I vacuum it I believe the fine particles will simply pass through and will remain in the water.
My thoughts are that the algae is gone because it "held" within 2 ppm overnight with maybe 3 total hours of sunlight added. Also, the water is crystal clear with a lot of "dead" stuff on the bottom. Does this seem reasonable?
What do I need to do today/tomorrow?