Inground pool plaster 12x60' 22,000gal covered Walnut Creek, CA
DE 60sq ft, 2hp primary pump, 1hp pool sweep pump, heater
Initial test after winter inactivity:
FAC 0 low
TAC 0 low
CH 250 OK
CYA 0 low
TA 80 OK
pH 7.6 OK
TDS 500 OK
Pho 0 OK
Ran filter continuously for 2 two days but water would not clear. Removed and cleaned filter panels completely (not backwashed). Added 6lbs DE. Shocked using chlorinator (powdered trichloro-s-triazenetrione) until FAC at 4ppm, CYA reached 30+ppm & added pt of HCl to destroy algae and contaminants. After 2 days of continuous filtering and brushing algae was killed and settled on the bottom. Brushed precipitates towards bottom drain. Started pool sweep but small screen trap becomes clogged with debris (should not happen). Eliminated air leak in pool filter trap lid that was causing air in the DE filter and reducing filter effectiveness. Continued to brush (difficult because we cannot see the brush or drain) and run pool filter. Water will not clear but remains milky/cloudy. Pool DE filter pressure approximately 10p/sq in.
The DE filter (Nautilus) is about 22 years-old, but the panels are only 2 years-old and in excellent condition. For some reason, the filter doesn't seem to be filtering properly. Is the milky water DE that is escaping the filter? The water will not clear even if we let the pool alone (no brushing or filtering) for 48 hours. We used our pressurized leaf catcher to remove silt from the bottom of the pool. The vacuumed debris looks like dead algae and some fine white, soft particles.
No amount of brushing and filtering seems to work. I think the filter is suspect. But we had it all apart and did not notice any defect in the manifolds and panels. Should we try adding more DE? Ideas anyone? I have read many posts on this subject, but none seem to treat of diagnose this problem.