1. You can use muriatic acid, as long as you do so properly, and make sure the pump is running when you add it. See http://pool9.net/muriatic/ for more info.

2. 1/2 gallon of bleach + 1lb of CYA /month may be a recipe that generally works out on S. Florida 7,000 gallons screened pools . . . but neither you nor I know that. the ONLY way to be sure your tech is right, is to learn to test your pool correctly. See http://pool9.net/testkits/

3. TFP (troublefreepool.com) is a copycat site of this one -- though now larger and in some ways, better run -- that started during a period when I wasn't taking care of business here. For the most part, they approach pools the same way we do here, since both sites follow the ideas I developed. But there are enough differences so that it will work best if you pick one site or the other to follow. If helps, I came up with most of the ideas, CarlD, who posts here, came up with a some of the nomenclature ("BBB method", and Chem_Geek, who has analytically validated most of the ideas, posts both there and at TFP. But whatever you prefer is fine -- just pick one or the other.

4. Liners are fine between 7.0 and 8.0 . . . depending on other factors, which is why you need the kit, just to make sure some of the other factors are NOT a factor on your pool. Once you test your calcium levels, you may not need to do so for another year.

5. Meanwhile, get a cheap local OTO / phenol red kit and some PLAIN 8% household bleach, and use the two together to get your chlorine level above 2.0 ppm.

I am interested in the fact that both your tech and your store acknowledge that calcium's not needed. When I started PoolSolutions in 1996, I was the ONLY one saying that -- so far as I can tell -- in the pool industry anywhere. So, at least one of my ideas is now widely accepted.