I'm not sure but I'd guess you'd want to watch your calcium level as well and keep it in the 200-400ppm range.

I also think you need to get a proper test kit. Look at PoolDoc's signature and click on the Amazon Links for K2006 Kits and that will direct you to what we believe is the best kit you can buy: the Taylor K-2006 FAS-DPD kit. If you go via the link a small portion goes to help pay for maintaining the Pool Forum. If, for some reason, you cannot get the kit via the link, Leslies Pools, from their online site has a clone, their FAS-DPD Chlorine Service Test Kit. It's the Taylor K-2006 re-badged in a Leslies box and costs a bit more but otherwise is the same.

The Taylor will give you one of the best pH testers as well as calcium, alkalinity and stabilizer testing. Plus the FAS-DPD system for chlorine testing, by far the best for home pool owners.

Carl