I've been making water on a newly setup system with a BRS 4 stage RO/DI. It works great, but I'm wondering if my inlet water TDS number which is usually 1, is normal. I get 0 out. On startup after sitting it may start on 11 but quickly goes down to 3 or 4 and eventually goes to 1 and stays there. I've always thought we had good water here in Portland ME, but could it be that good?