DIY rocks and slow climb PH

Are you topping off with the well water? If so, you're just building up all the extra bad things, like copper, over time until you have an inevitable crash. At the very least, start getting distilled water for topping off, but honestly it's really best to get a ro/di unit or you'll likely have problems in the future even if you use distilled for topping. I especially wouldn't try to start a reef system with well water.