The problem with that Harley is that the test strips YOU used were
really a far better quality then the extremely basic G&H ones this poor schlep is using! Medical grade test strips are medical grade price!
In the past I have found HANNA inst. to be the best maker of testing meters. I still have a very costly, lab quality, Hannah soil pH meter.......As a farmer and a medical grower. This unit is, bar none, the best REAL (portable) soil pH meter I have ever used!
I still have my Hanna multi meter but, don't hydro much at all any more.
You NEED a good pH meter FIRST!
HERE is a working pH meter for CHEAP that work's quite well.....BE SURE to keep the tip wet with RO or storage solution! Only $37.00!!
https://4hydroponics.com/hanna-instruments-checker-1-hi-98103
I never understood why people pay such attention to an EC or TDS meter! Simply follow the nutrient makers feeding charts and adjust use down or up as needed! Thats all EC or TDS is is the concentration of nutrient IN the water. The thing to remember is that water will HAVE an EC or TDS of it's own and you simply don't KNOW what makes that up as in contents! RO has nothing and is the best starting point FOR hydro -
period . YOU put everything in (including your own buffers) and the plants do the best with RO....
Save your coins IF you decide to stay with hydro and spend them on this meter (if you REALLY feel EC/TDS matters to you) - the best there is for what it's made for. THIS IS YOUR GOAL
https://4hydroponics.com/hi-98129
So then - spend the $37.00 plus shipping and have a wonderful cheap pH meter that works and adjusts well.....just don't drop it in the res! LOL AND save the EC/TDS for later if you really want it!
Doc
P.S. As a farmer and a past manager of a Yew farm for a well known drug company.....I do not like BlueLab equipment.....I have had more problems with Blue lab over HANNA and that goes all the way back to College......By the way, MSU and it's extensions, use HANNA testing equipment (the last I knew)....Doc