Hello! First I'd like to send a blanket "thank you" to the pool wizards here. Your seemingly endless wealth of knowledge has gotten me started, and I'm excited to learn more!
Here's the scoop: my wife and I just bought our first house. It was built in 1956 and we are only the second owners, and from what my neighbors tell me the pool had not been opened for a good 7-8 years. It's a monster, in-ground concrete pool - 20' x 40', about 35,000 gallons. To add to the fun, the "cover" that was on the pool had gigantic rips running through its center, so it was not actually preventing debris of all kinds from getting into the pool. Needless to say, we had a serious swamp on our hands (and still do).
I am currently SLAMing the pool following this forum's advice, and things are clearing up slowly but surely. In the last few days, however, the pressure on my filter has been skyrocketing to the point of needing to be backwashed 2-3 times per day. (Normal pressure is around 20, and I am backwashing at 28-30.) Is this normal? If not, what's the next step? It's an old sand filter -- is it possible that the sand needs to be changed? I have no idea when it was last changed, if ever.
Current numbers, if they help, are roughly:
pH - 7.2
CYA - 30
FC - 12 (SLAMing level)
CC - 1
(All measured with a Taylor K-2006 kit)
Thank you in advance for your advice!