Evaporation changing chemical concentrations

[mas985]

If you never replace the water and let the water level drop, then yes, the remaining chemicals would become more concentrated. But that doesn't typically happen in a pool. Most people replace evaporated water with fill water which then dilutes the chemicals back to where they were before the evaporation but with some added components. Fill water will normally contain CH and TA so over time CH and TA will climb.

[nefretrameses]

Makes sense. I guess I thought so. Unless fill water CH & TA were zero, the concentration will always climb.

My finish was being etched from low CH & PH, but I didn't know it until I came here. I got my CH up to 250 last week, so I'm hoping the "sand in the bottom of my pool" diminishes and stops.