Hi, this is my first time posting though I have used answers on this site so many times, so thanks for that! This is the third year we've had our pool (20K gallons, vinyl liner salt pool, sand filter, variable speed pump) and for the first time in those three years the pool is cloudy. I have a pool service open and close the pool but I balance it throughout the summer. This year when they opened it it was pretty clear but with some debris on the bottom. We had a truck add water to bring it up to the skimmer. They did the initial balance and vacuumed to waste. As soon as they finished it was milky white and 7 days later I can still barely see the main drain cover. It is balanced properly, pH is 7.2, Ca 120, alk is 100, cya is 40. They added a lot of salt, 3900 by the meter on the salt cell, 3650 by my strip test (I don't have a salt test in my test kit). The free Cl is about 12 (they put 4 Cl tablets in the skimmer and due to the cold weather here (40's) I let that circulate and only turned on the salt cell yesterday since levels were so high).
The pool company told me that the problem was that the sand in my filter probably needs to be replaced. I have backwashed even though pressure from the filter hadn't increased above about 12 psi, and didn't noticeably decrease after backwashing. I thought we needed to add more water due to the high salt but the pool company says it's not high enough level to be a problem. It has not gotten warm here (above about 62) until recently, so I don't think it's algae given the good pH and high CL levels. I don't know whether to have the sand replaced or try something else like a flocculant (the pool company also said that a sand filter may never be able to remove the cloudiness, I might just need to get a cartridge filter). Any advice greatly appreciated!
The pool company told me that the problem was that the sand in my filter probably needs to be replaced. I have backwashed even though pressure from the filter hadn't increased above about 12 psi, and didn't noticeably decrease after backwashing. I thought we needed to add more water due to the high salt but the pool company says it's not high enough level to be a problem. It has not gotten warm here (above about 62) until recently, so I don't think it's algae given the good pH and high CL levels. I don't know whether to have the sand replaced or try something else like a flocculant (the pool company also said that a sand filter may never be able to remove the cloudiness, I might just need to get a cartridge filter). Any advice greatly appreciated!
