Well, you should not be using a zapper to make CS. There are a lot of reasons why. First you need a constant current generator. The voltage should be 30 volts. A stirring device is critical during brewing. And, a TDS/PWT meter to let you know when you have reached 20 PPM. Anything over 20 PPM becomes problematic, so I am told. Then you should have a laser pen to check the tyndal effect.
You could definetly do better! Hey, I made a lot of junk CS too, before I got educated. Good CS is wonderful. Bad CS is useless.