Just bought a new hot tub. Set it up bought Leisure Time Granulating Chlorine, Spa Up, Spa Down, Alkalinity, Replenish and of course test strips. The guy at the store said fill spa with water before my water softener (I have well water) I did so let it get to temp put chlorine in and tested. It took a bit to get things somewhat right Alk was high, PH was high and Calcium was low. I finally got the Alk and PH within range but the calcium won't come up and it seems it always need chlorine. My confusion comes in at the point where I have that sandpaper feel on the inside of the tub and the returns seem to have white build up on the lower holes. But the calcium is low at about 100ppm. Everything I read says the Calcium should be high with this sandpaper issue. Please help. I'm a novice that wants to have things right and I'm becoming very frustrated. Thank you in advance.