Well, pH varies during hte day anyhow, so if you do religiously test it, you need to take that into account (early morning, pH will be lower than late in the day, as CO2
will build up overnight, dropping pH, and then get consumed when the lights come on and the algae sucks CO2
I too am not good about testing pH. pH is one of those things i assume is 'good' because i have argonite sand, and do regular water changes with proper salinity of water.
But the long and the short of it is that using argonite based sand should eliminate the need to mess with your pH. If you use tap water, you could run into problems, which is why I always suggest R/O water for a salt tank...you have neutral water that'll accept thet pH and buffering that your salt mix provides.