I have a 15'x48" above ground vinyl pool. I'm using the BBB method and I do a full test every 24-48 hours and a chlorine test every morning and evening. My water clouded up a bit about a week ago and I haven't been able to get it to clear up. I don't want to add unnecessary chemicals is I don't need to so I haven't done anything aside from adding bleach as usual. My test numbers have been steady for a few weeks. As of last night they where:
PH - 7.5
FC - 6-7 (have to run a dilution since my tester only goes to 5)
TA - 110
CH - 170
CYA - 40
The pool temperature drops to as low as 75 degrees at night and usually averages 78-82 by the mid-afternoon. I don't know if the temperature swing can cause a problem, but I don't know how else to combat that; it's just a part of living in the desert. I don't notice any algae growth on the walls and I am getting solids at the bottom requiring me to vac daily. I clean the filter (the cheap-o paper filter system that came with the pool) daily and make sure it is moving enough water through. The pump runs for about 8 hours a day on average, sometimes up to 12 hours. The water isn't entirely cloudy, but underwater visibility is only a couple of feet tops.