Please help me with my EC meters!

[Porky101]

Hi Everyone,

I wonder if anyone can help me. I have 3 EC meters :

https://www.amazon.com/UBANTE-Professional-Temperature-0-9990ppm-Accurate-Aquariums/dp/B06XC6CV9J/ref=sr_1_28?ie=UTF8&qid=1491859318&sr=8-28-spons&keywords=EC+meter&psc=1

&

https://www.amazon.com/Bluelab-Truncheon-Nutrient-Meter-Germination/dp/B00348PV6S/ref=sr_1_1?ie=UTF8&qid=1491859307&sr=8-1&keywords=bluelab+truncheon

&

https://www.amazon.com/Oakton-Waterproof-EcoTestr-Conductivity-Tester/dp/B007FFFTUO/ref=sr_1_23?ie=UTF8&qid=1491859318&sr=8-23&keywords=EC+meter

The UBANTE measures in Us.
The Oakton measures in mS.
The BlueLab measures in EC, CF, PPMx700, PPMx500.


I am trying to understand if perhaps my truncheon meter is not working correctly. I will explain why:

I have conductivity testing liquid:

1x @ 2.77EC
1x @ 1.4 EC

If I use the UBANTE in the 2.77EC solution I get 2900uS
If I use the Oakton in the 2.77EC solution I get 2.8mS
If I use the truncheon I get I get HALF the reading of the EC solutions!?!?!?!?!? So in the 2.77EC I get 1.4EC reading. on the 1.4EC I get 0.8 reading.

I suspect my truncheon is broken, however I have been using it to feed my plants. Currently my Truncheon meter is readin an EC of 1.4 for my girls in VEG. They look fine, ZERO BURN. If the REAL EC was DOUBLE, then that would mean that the EC was 2.8 in coco, I would have burn on my plants and wilting...my plants look great....definitly does not seem to be getting an EC of 2.8.

If I use the other meters the readings I get are 5.3mS and 5,000 uS.


Are my other meters reading too high?? (although they are reading the conductivity standards fine).
Is my truncheon brocken???? I have tried cleaning it with the same results..??? I have always fed my plants with an EC of 1.2-1.4, but these other meters are confusing me???



Thanks for any help or suggestions!!!

 

[mjinc]

2.8 EC is high but some strains handle strong feeding schedules. If the testing solution is showing the correct value of 2.77 on the other two probes then they are working correctly.

 

[Atomizer]

Have you cleaned the contacts on the bluelab lately?

 

[Porky101]

Im an idiot.

Never cleaned my contacts.

The bluelab pen is reading the conductivity standards correctly now.

My plants were being fed EC 4.2 water!?!?!?!?!?!? I have lowered it back to 1.8.

I think they have been being fed that for the past week only. For some reason not a lot of burn...
Luckily im in COCO, if I was in strait DWC or AERO my plants would have all been dead.

 

[Atomizer]

I`d be tempted to do a quick flush.
Aero plants show symptoms sooner but recover quicker once the issue is fixed

 

[Porky101]

I`d be tempted to do a quick flush.
Aero plants show symptoms sooner but recover quicker once the issue is fixed

Im growing in coco, whenever I water I water until I get runoff, so I just watered twice with EC 1.5 water.