You can get by pretty good with no PPM meter but a PH meter is so easy and acurate. I had a couple high dollar ones and they coast too much to keep up. Here's some that I get 2 or 3 at a tme just to have. Give one to a bro when he drops it in the water. LOL.

pH METER (Hand Held) Milwaukee pH600
Don't forget the calibration solution. and gets some good ph up and down.

Once you use a meter you will wonder how you got by with out it. No muss no fuss.