Hi, Jimmy, and welcome to the Pool Forum!

I'll have to let someone else answer your question about your fiberglass repair because that is something I don't have the answer to.

As for your question about stabilizer -------- it would help if you could provide some current water testing results taken with a drops-based kit and we also need the CYA reading. It is true that without enough CYA in an outdoor pool, that your chlorine is quickly lost to the sun. But, before I can recommend that you add more CYA, I really need to know your current level.

Do you have a good kit? The test kit that we think is by far the best is the Taylor K2006 or 2006C (better buy). Not available locally but you can get it through this link that takes you to Amazon: http://pool9.net/tk/ Having this kit makes it so much easier for you to maintain your pool without having to depend on a pool store for testing. (Most pool store testing is not very accurate. Think about it. They are in business to sell you stuff so they have no motivation to tell you that everything is ok even if it is.) It also makes it much easier for us to be able to help you.

In the meantime, if your pool store uses the "disappearing black dot" CYA test, ask them to test it for you for now and report the reading and then we'll better be able to advise you as to whether or not you need to add more.