Difference between PPM Meter and Recomended per manufactuer

I bought a new PPM meter on eBay, I wanted to be very accurate on my PPM. I had beeen mixing nutes per instruction from manufacturer. Then after getting the PPM meter, I was shocked on how wrong the manufacturer was.

Readings that the manufactuter was recommending were way to light.
B'Cuzz Growth recommends 1 ml per liter. I was putting 6 ml per gallon which should be about 1000PPM. My meter read 99 PPM.

KoolBloom recommends 1/4 teaspoon per gallon, PPM meter reads this at 250PPM.

Is this normal? I calibrated the PPM meter twice, it's right. I'm assuming a meter is more accurate and the manufactuer is keeping these low to prevent burning.

Here is the meter:

HANNA Primo TDS Meter, PPM Tester, Conductivity - eBay (item 370058747099 end time Jun-14-08 16:25:22 PDT)


I'm a soil grower and wanted a bit of advise based on our prior experence.

Thanks for you feedback!!

Water out of the tap is more than 99 PPM, i would guess you are at the limit of your meter 1999 and its only showing the last 2 digits

No, it's a Hanna PPm meter and calibrates correctly. I guess my question is do I trudt a PPM meter or what the nutes company says.

Trust the nute company because you meter is broken,

Unless you have RO water spewing from your facet and you think a ML is a microliter, then your PPM pen is broke...

Trust me on this one,

Go to your local grow store, tell em you have only $45 and you need a PPM pen, theyll most likely give you a millwakie pen, but it will be correct.

newbie needs help plz.bought a oakion made by eutech instruments.it has this calibration solution the way i read the instructions is dip probes into solution and calibrate it to 1500 .is this right??? using dutch master nutes so now do i just put it in like the bottle says and read the ppm and add r dilute nutes..can some one pm me need some help stores closed gotit at jollygreenhydro.