no I'm going to buy the drinking water from water store not Tong....I only buy the premix saltwater from tong as I have....but I've learn now that mixing is a lot better because the nutrients in the salt mixes is more abundant than buying premix water from the LFS....
I see, well definitely Get a TDS meter.
The only major differences in salt mixes are the amounts of cal, alk, and mag. Some LFS sell Catalina water or Natural Saltwater, which is low in all three and is usually sold for less as compared to for instance Tropic Marin or Red Sea to name one or two. Some mixes have more calcium or alkalinity, etc. To each their own when it comes to that. Its finding your balance and sticking to a routine is most important.
Stealing from Greg Carroll, "SPS- Stability Promotes Success". By adding things quickly and not getting a handle on proper husbandry and water quality you will have a tough road. Our hobby is challenging enough...