I recently began to have black algea in my pool. Fortunately, it was not rampant, but there were a couple decent sized spots on the wall (probably an inch in diameter) and then some much smaller dots starting to scattered around. So, I knew I needed to do something about it before it got completely out of control.
So, I bought Black Algea Killer. Yes, I bought Leslie's and I know from reading a bit in this forum now, probably not the best option. That said, it did a pretty darn good job and even those large spots have disseminated to barely visible brownish spots and all the small little spots are basically gone. Still some around the bottom drains, but that's hard to get to and brush well (8ft deep there).
I will confess that I overdosed it. The recommendation is 12oz for 10k gallons. I have about a 16K pool and I probably used 24 in the first treatment. That was in the evening. The next morning not too much progress, so I wire brushed everything again and did another slightly smaller treatment - probably about 18-20oz this time. So, total algecide within 12-13 hours was around 40oz+. I just wanted to attack it. And, for the most part, it worked great.
Now for the foam and swimming...the last morning treatment was two days ago, so about 60 hours ago. I got the initial foamy effect from the doses at the waterfall as I expected, but it dissipates as the water swirls around the pool. It is still happening. I have lowered the water level a couple times a few inches each time (to just above the skimmer opening) and added fresh water. Still getting some foamy effect (really more like bubbly bath water) from the waterfall and when I splash with my foot, there's some bubbles for sure. But, it's really only spread out from the fall now about 6 feet or so before it dissipates. I just know there's probably still a significant amount of algecide in there.
Here's a pic of it's current bubbliness (sorry it's sideways):
I understand that the foamy bubble stuff should hopefully subside on it's own over the next week. But, I have a couple questions...
First, is it safe to go ahead and go swimming at this time and, if so, can it be lengthy?
Should I do anything like rinse the filters and tank, or is it O.K. to just let it do it's thing over time?
Pool Type: In Ground
Shape: Kidney Bean
Pool surface: Gunite
Approx size: 15.5 - 16K (15 x 30 x 8ft deep end/just under 4ft shallow/steep mid pool decent)
Filter system: Hayward Smart Filter 450 (4 new filter cartridges recently installed)
Chlorine: Currenty 3.0+
PH: 7.7ish (working on lowering that a bit)