I know you don’t know me but I wouldn’t steer you wrong.
Apera is a very high quality line of meters.
I love mine.
Extremely well built and extremely accurate. I
I use this one for my PH;
Apera Instruments PH60 Premium Waterproof pH Pocket Tester, Replaceable Probe, ±0.01 pH Accuracy, -2.00-16.00 pH Range https://www.amazon.com/dp/B01ENFOIQE/ref=cm_sw_r_cp_api_XwH-zb1WQDTNG
And this one for TDS/ PPM. ;
Apera Instruments TDS20 Value Waterproof TDS Pocket Tester, Accuracy: ±1% F.S, 0.5˚C, Complete Kit https://www.amazon.com/dp/B01ENFOIN2/ref=cm_sw_r_cp_api_2yH-zbJ2YJQZH