Good morning. I have a SWG, 20,000 gallons, Pebble Tec.

I am having some trouble keeping chlorine in the pool. Usually I do not. But I live in the Fort Worth, TX area and it has been 100-107 degrees everyday for a couple of weeks. My latest chlorine test was in between 1-2. I was able to keep it higher just a few weeks ago when it was not so hot. My CYA level is 40-50 which is usually good (I was keeping my chlorine at 3-5). I have been running my pump 11-12 hours a day and all seems fine (no error lights, salt cell is very clean-no scale). I even superchlorinated earlier this week. I decided this morning to add some granular shock...not a whole lot though. I also decided to put in more CYA because I thought maybe I did not have enough "sunscreen". Is this the proper course of action? I have very clear water and the other readings seemed fine (alk-90, pH-7.6, hardness 250, less than 100 phosphates).

This kicker is that I am going on vacation for a week beginning tommorrow. I do have a house sitter and I am going to leave him some pool care instructions (I will also leave the chlorinating % at 90%). Should I just tell him to add some shock every few days? Any help would be great?

Thanks,
Mike