Ph pen / ppm pen accuracys?

BlueBerryMango

Active Member
well damn!!!! My ph pen dropped into water so I bought a new one....along with a new ppm /EC pen!

While making a solution to see how much PPM is in it due to the fact I added alittle CAL/MAG.

No calibration pens even though I thought with this new one I'd have to calibrate it.


The ppm with one pen said 500 for example, while the other says 750!
How do I tell which is more accurate??
The old pen says it can read past 999 but it doesn't show it on LED, while this new one shows it could actually read up to 9999.
I'll likely use this new pen as it shows the higher number and it's always safe to under feed then over feed.
But still how to tell which is more accurate or whatever the deal is with these PPM Pen?
 
Top