Keeping your chlorine at shock levels is almost impossible to do when you have multiple days of thunderstorms. I would just maintain 4-6 ppm chlorine in the pool until you're going to get a few days of sunshine, then take advantage of that time to remove the cover, shock the pool up to 15 ppm and hold it there by testing/adding more bleach as many times a day as possible until the algae is dead. When you can test after sundown and again before the sun is on the pool and not lose any chlorine, then you can let your levels drift back down to the 3-6 range--but you're going to have to keep it above 3 ppm at all times to keep the algae away.
Janet
Edit: Just reread your post again and saw the well water/metals issue. If you have orange/brown staining in your toilet tank, then you may need to add a metal sequestrant to your water before shocking, to keep the iron in suspension and keep it from staining your pool. Might want to read some of the threads in the metals forum before shocking, so you'll know what to look for.
Bookmarks