Here is the "shot glass method": You can double the reading to 10 by mixing equal amounts of pool water and steam-distilled water. I like to use the "Shot Glass Method" --One shot of pool water, one shot of distilled water. Mix and now measure. If the reading is "5ppm", you have 10ppm. You can keep going - 3 shots will take you to 15ppm and so forth. You will not be able to test for combined chlorine with this method.

The test strips aren't too accurate, but the regular drop based kit with just chlorine and ph will be ok for testing with the method above for now. If you do have a cya of 30 to 50, then you need to have your chlorine at 15 to get to shock level. You will have to keep it there for a couple of days until you clear up all the algae. It is best to keep the chlorine level constant, so you should check at least 2 x a day - 3 times is better. Once you are holding chlorine overnight, then you probably have the algae killed. But since you can't test for combined chlorine right now, you should keep the chlorine levels high for a couple of more days. Remember to backwash and keep your filter running 24/7. Keeping your ph low is ok for now, because chlorine is more effective with a low ph, so I wouldn't worry about raising it for now. You can brush and vacuum right now - the more the better. Your water will clear with high chlorine levels, constant filtering, and regular backwashing. Oh yeah, did I mention patience? I always hate that patience thing!



Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm