According to pool builder there is nothing to do about the white line on tiles. It's our fill water. Can this calcium destroy the tiles and grout if left untreated? I called a tile cleaning service and they want $749 to bead blast.
Most of the white is above the waterline at this point, and on the sides of the spa spill over, so I doubt lower csi will remove it. The question is will this cause permanent damage to the tiles and grout if not treated.What's your CSI? Keeping it slightly negative is best.
If the salt level is at 2600 ppm is that considered soft water?The scale will not harm the tiles. Depending on if the grout is cracked and the water is being wicked up the grout, the scale can weaken the grout.
Managing CSI is paramount with high CH. Better is to use softened water for make up water.
We pretty much gave up on the solar cover idea because of the strong winds in Apple Valley, California. It took us for a ride when we tried it out, not fun. I do use the csi, currently my CH is 400, PH7.8, Alk70Then you will need to manage your CSI as your CH rises. Once CH gets to about 800 ppm or so, you drain and refill. Few options. Use a solar cover especially in the spring (March-May) and fall (Sept-Nov). That will reduce your evaporation during those times and keep your pool a bit warmer.