Rely on the drops based test. The 5/10 chlorine reading is really 5ppm - OR 5 TIMES LOWER THAN YOU NEED.

Right now just test the chlorine and PH. The CYA and ALK and CA shouldn't change that much.

If you have the OTO test (which is the one that is yellow)- get some distilled water from the store and take one part pool water and one part distilled water. Mix them together and then test and multiply your results by 2. This will allow you to test to 10ppm. If you take two parts distilled water to one part pool water and then you miltiply your results by three (15ppm)....and so on.

Otherwise I would recommend a FAS-DPD test kit for the high chlorine levels. Call your pool store before you drive all the way out there to see if they have one.