Hello and welcome to TFP. If your liner is bleached from a pool store product that rested on the surface, I suspect the color is gone. But rest-assured we can help you maintain your pool the right way, easily, and with common grocery store products. If you are committed to this, then do the following:
1 - The proper test kit (i.e. TF-100 – link below) is the foundation of your pool care. Why this kit? We've learned through personal experience that you cannot reply on pool store testing, test strips, or simple over-the-counter kits. They simply do not read Free Chlorine (FC) or Cyanuric Acid (CYA) levels accurately or to the high levels we need. If you do not have a TF-100 or Taylor K2006 test kit, it should be your #1 priority.
2 - Read all the links you see below in my signature. They contain everything you need to know.
Golden rule - Avoid the pool store for testing, advice, or products. You simply won’t get the advice/service you deserve and you will waste money on products your pool doesn’t need. Do not add anything to your pool other than what is advocated by the TFP site or its experts. You’ll have a happier pool, spend less time maintaining your pool, and probably save some $$ in the process. The following are short articles from this site that you will see linked in my signature below: Pool School, Recommended Levels (for YOUR pool), PoolMath Calculator, SLAM, and the Chlorine/CYA Chart. Welcome!