What's up Nick? Glad to see you're still at it, one thing I'll give you brother is that you're not bullshiting. You're really trying to have the best set up you can for your 1st run. I hope everyone else can see that too.
Ok so I know you've picked a different fertilizer but I still want to answer your question from the OP just to kinda clear the air. You always need both PH and TDS meter. Even if a master of marketing hype company like AN can make a "PH perfect" line of snake oils you still need to test for a few reasons
1. (PH) How can you know for sure? Things can happen in your medium/system such as build up and that will change the PH of anything you put in there.
2. (TDS) Even AN can not account for grower error. AN does not claim to save your plants from being over fed as most new growers will do(check out gunnar&carey all his problems come from him not being able to leave his plants alone)
3.(RO) You need to test both PH/TDS of your RO water alone. How else will you know when to change the membrane or filters? When the filter gets dirty your TDS will rise and as a result it'll affect the PH of the water as well.
Basically always test, even if you're not going to alter anything you should still test just to "know" what's going on. Don't forget to log that shit either! Get a notebook and write it down. I also always test my tap water to see where I start out at, I've notice that my tap water changes through out there year.
Hope this helps, good luck as always and happy growing!
Fuck A.N. I'm using GH flora series 3 part micro grow and bloom. Wondering if I can add stump tea to my hydro setup with GH nutes? Thinking about ordering stump tea also for my rdwc.