Having owned an IG 13K gal pool in So Cal for 20yrs, I've finally had enough of blindly following the recommendations from my local corp pool store. Nothing against the people working here, understandably their agenda is to keep the store open and pay their employees. Hey, and I own some/a lot of the blame for not seeking outside input, or on line self education such as this forum. By regularly checking in on the forum, and referring to pool school, believe the tools are here to become self sufficient at maintaining a properly balanced, healthy pool, and even save some money.