If you put in 33 drops, then your chlorine is actually 16.5 (if you used the 10 mL sample). You divide by 2, instead of multiplying by 2. I would add CYA to around 40-50 ppm, but otherwise your numbers don't look too bad. If it's a concrete pool, then your calcium needs to be 200-400 ppm, but you didn't list that. If it's too low, then the water will leach the calcium out of your concrete finish and make it brittle.