Reefers not using a controller...

[Aquattro]

I just can't see checking pH ten times a day. That would last for about a day, then I'd feel I wasted money on a silly controller when I ould have bought more corals!
In 2004 I had a full time pH meter. Every day it said somewhere between 7.9 an 8.4. yup, right where I want it. If pH gets too far out of this range, you're going to know it by your corals behaviour.
Temp, same thing. Set your good quality heaters, check them monthly to ensure they're working, temp is going to stay stable.