Do you have a water softener for your home? Many of us top off our pool's evaporation loss with soft water, to avoid the problem you're having. Every time your pool fills, you're adding more calcium. It doesn't evaporate with the water, so it just builds up. You can replace water periodically to try and lower your CH, but you'd be replacing it with calcium-rich water! It's very tough to control CH that way. Some here even have a dedicated softener just for their pool.
My pool finish was destroyed by a careless "pool guy" and my city's hard water. Since taking over the pool (after replacing the finish) I no longer have any build up on the pebble surfaces. It's been about six years. Just his last year I replaced about a foot of water to bring my calcium back down, but that's it. No build up on my SWG. Nothing on the finish. I get some crud at the water line, but that has more to do with evaporation than it does chemistry.
Don't try to save money on a cheap test kit. Get one of the two we recommend. It'll pay for itself.
I was on a mission to see how I could shave my pool maintenance tasks, and have it down to about 10 minutes a week, most times less. My water and pool are way better off with me doing it. As yours would be. And I save about $1500 a year! Surely you can find 10 minutes a week...