My pool is still green but getting better everyday. My question is since my pool is fiberglass I been using Jacks purple stuff all season last year to keep the stains at a minimum. Should I use it now or could I wait til pool is balanced?
You can add sequestrant any time. If you are trying to remove existing stains the other levels are very important, but if you are simply adding it as a precaution against future stains it is fine to add any time.