Hello all! First time pool owner and trying to get a grip on pool chemistry. So much conflicting advice between pool stores, weekly maintenance people who just stop showing up and well making neighbors friends and family. Hard to determine who to believe. Hoping to learn here and get this under control. Pool is almost 2 years old and battling calcium line at water level. Pool store says hardness is at 900. Went from 398 to 900 in 1 month. I am figuring it is high because as I work on the calcium line with pumice and rinse with the pool water I am getting a white residue on all tile rinsed with the water. Considering reverse osmosis truck to get this in check. Just ordered the T100 test kit as well. I was using the Poolmaster 5-way but it doesn't test calcium hardness and the other readings are very different from the pool store and weekly maintenence people. Any advice greatly appreciated, I am going to beat this and learn to maintain my pool myself!!!