Yea I feel you man. I went through the same shit and then eventually bought a Bluelab combo meter. Best investment EVER

lol.
Low humidity around 40% in the flowering stage is good. It will protect you from any Botrytis (mold) issues and also frost up your buds. In the last week i even push mine down to 30%.
Look into “BLUELAB” truncheon/ ph meters. They are reliable. And if you can manage it, then grab a BL combo meter. It BANGS !!