I’m near my wit’s end.
I’ve been using the BBB method for 5 years and it has been very successful. However, I’m having a problem this year holding chlorine.
This is the 3rd time in a row this situation has happened this season. Here’s the info for the latest occurrence:
Readings as of 7 AM this morning, June 25th
FC = 9.5
pH = 7.6
TA = 140
CA = 300
CYA = 40
Ammonia = 0.0
Phosphates approx. 200 pbb
6/23 3:00 PM – Brought the pool up to shock level (16 ppm)
7:30 PM – FC = 16.0
Ran the pump all night.
6/24 6:45 AM – FC = 16.0 (OFCT seemed to be successful.)
1:45 PM – FC = 15.0 (Opaque covered had been closed until 1:45 PM)
5:30 PM – FC = 13.0 (Pool had been exposed to sunlight and 4 teenagers for 3 hrs and 45 min.)
7:00 PM – FC -= 12.5
Pumped turned off at 7:45 PM
6/25 6:00 AM – Pump turned back on.
7:00 AM – FC – 9.5 (Lost 3 ppm in 12 hrs while the cover was closed and the pump was off)
This is the 3rd time in a row that this has happened. Overnight Free Chlorine Test indicates there are no algae in the water. Then over the next day or two the chlorine level drops significantly indicating there is something consuming the chlorine.
I’ve pulled the light and cleaned behind it. I’ve brushed the entire pool. I’ve swam using a mask looking for any discoloration on the liner and found none.