Having a rough time this season so far. Pool was opened and proper chemicals added, NOT VACCUUMED (lots of leaves on floor). Water got clear in hours. Heater turned on. Two days later the heater somehow caught fire and whole front-end melted - landscaper saw the fire and extinguished. Doesn't seem like it was a gas fire. While heater shopping, I didn't bother with chemicals or vaccuuming - water went very cloudy and light green. New heater installed and chemicals brought back up to par, confirmed via water test performed by Leslie's. Water got clear but stayed HIGHLY cloudy. Shock added, no clearing of cloudiness. Filter runniing about 24 so backwashed and it came down to about 16 and Returns pressure was restored. One day later, still highly cloudy. Pressure went back to mid-20's so I backwashed again. Again, down to 16. Clarifier added - no luck. DE added - no luck. Still very cloudy. I'm now playing yo-yo games with the filter.... it goes up to mid 20's, I backwash, it goes down to about 16, then it goes back up few hours later.
Does this yo-yo'ing of the pressure mean it's time to replace sand? That's the only thing I can think of. Originally I thought maybe the fire's soot was being pushed into the pool, but now even with the new heater, same thing.
All help will be appreciated tremendously... very frustrated at this point.
Inground pool, chlorine, approx 12k gallons, sand filter, hayward ng heater: new, 2 skimmer baskets, no main drain, hayward superpump: new last season