Hanna Combo GroChek ph readings

[solarz]

Hello MP community,
i'm posting this thread because i am having some issues with taking the ph readings on my new Hanna HI 991404 combo meter. The issue that i am having is that the ph reading never stabilizes and stops climbing. I read the instructions and it says that i should take the reading when the stabilization indicator goes of and when it goes off, the reading doesn't stop...it keeps getting higher. Does anyone have any experience with this combo meter, or any similar to it? Or does anyone have any suggestions as to how to take an accurate reading. I'm affraid to get anything started until i can get a correct reading.

BTW, i can get it to stabilize (at least for a few seconds) when taking ppm or ec readings, its only with the ph that i can't seem to get it to stabilize. Thanks in advance.

solarz

 

[Growdude]

Did you calibrate the meter?
If you did did it stabilize when you did?

 

[solarz]

Sorry, i forgot to mention that part. I did a two point calibration with 7.01 and 4.01 and i got it to stabilize and calibrate correctly then. It was after that when i started having the issue with taking the ph reading.

 

[Growdude]

Sorry, i forgot to mention that part. I did a two point calibration with 7.01 and 4.01 and i got it to stabilize and calibrate correctly then. It was after that when i started having the issue with taking the ph reading.

Well not sure but they do make a cleaning solution that might help.

Does it fluctuate now if you use say the 7.01 solution?

 

[HippyInEngland]

The Combo HI 991404 series meters from HANNA instruments are designed for continuous, high accuracy pH, EC/TDS and temperature measurements. These microprocessor indicators continuously monitor the three most important nutrient parameters in hydroponics, greenhouses and horticultural applications with a single instrument. These indicators feature a large, dual-level, backlit LCD to give you instantaneous readings of pH, EC or TDS and temperature, even from a distance. At startup, these indicators perform a self-check to assure proper working condition. HI 991404 stability indicator and hold features prompt the user when to take the reading and freezes the display for easy and accurate recording.

Calibration and temperature compensation is automatic, while the EC/TDS conversion factor and temperature coefficient (ß) are user adjustable for application-specific measurements.

These instruments are supplied with an advanced, non-clogging double junction pH electrode and a rugged conductivity probe that will withstand even the most aggressive environments. The instruments are powered by a 12 Vdc transformer and are easy to install and use, making them ideal for all continuously monitoring applications.

Range pH 0.0 to 14.0 pH

Range EC 0 to 3999 µS/cm

Range TDS 0 to 2000 ppm (mg/L)

Range Temperature 0.0 to 60.0°C (32 to 140°F)

Resolution pH 0.1 pH

Resolution EC 1 µS/cm

Resolution TDS 1 ppm

Resolution Temperature 0.1°C (0.1°F)

Accuracy pH ±0.1 pH

eace:

 

[solarz]

Thanks Hippie...i knew it was a continuous meter, but i thought i was doing everything correctly...maybe i need to re-read the section about hold/freez capability.

BTW, they don't really give you all that detailed of instructions about the functions of this thing. LOL

 

[BuddyLuv]

Is this the little pen style?

 

[solarz]

No it isn't a pen...it is a continuous meter with separate probes for ph and tds/ec.

 

[311Grower]

stick that bad boy in 7.01 solution and see what it reads. When was the last time you calibrated it?? I don't really have any idea what it could be, see if you can find Hanna's tech support and call or email them.

 

[solarz]

I've been having some issues with my meter. I've been trying to take readings, and i've noticed that it just didnt seem right. So i placed the probe and electrode into the calibration solution (7.01) and it gave a reading of 6.01. So i figured i'd calibrate...and this is where the problem comes. When i try to calibrate the meter, it wont calibrate. It tells me to use the 7.01, and when i put it in the solution, it just does nothing...the "CAL" symbol just flashes, and it doesn't recognize the solution at all. I tried it again, but this time using the 4.01 and it did the same exact thing. Does anyone have any idea why this could be happening? I really need to check the ph and ppm of my taks before moving my newly sporuted beans over. Thanks in advance.

solarz

 

[JBonez]

i love my hanna meter, the probe is convenient, and i just use the storage solution when im not using it, btw, the ph will fluctuate a bit, but as you use it more and more the readings are faster and it stabilizes faster, the tds portion always seems to fluctuate tho, hope that helps.

 

[medicalGreenGrower]

i've got the above meter and i have a similar problem. it has a little stop watch in the upper left display that tells you when it's stable and you can take a reading but after the stability wait light goes out, the pH keeps rising or falling. i've held it for 3 or 4 minutes and it just kept going up and up or the other way. i was wondering why i would pH my water and be one drop of pH down away from 5.6 and after adding that drop, i'm suddenly i'm at 4.3. i just replaced the pH probe and i still have the problem. i did notice though that after using it for an hour it started working a little better. i'd rather not do an hour of testing 10 times and averaging a guess at my pH to finally get to a point where my meter works though. has anyone else had this problem and fixed it? thanks.

mG2

 

[solarz]

I'm sure glad that you posted that, because i thought i was just going crazy. I don't ever hear anyone having issues with the ph/ppm reader...and i've had a world of issues with mine. Its only about 2 months old, and i've actually been using it off and on for those 2 months. I can get a pretty steady ppm reading, but the ph is just a guess. It never stabilizes, and it will easily (and frequently) jump from 5.5 to 3.3 and then right back up to 6.3. I've also had an issue where the reading just starts blinking with "0.00" showing on the display. It willdo that until i move the probes around. And one more thing, i also get different readings depending on how far my probes are into the water. Is there a specific way that you are to take the readings? I've read the entire manual, and its rather vague. Any and all help would be greatly appreciated. Thanks in advance.

solarz

 

[solarz]

Thanks bro...and honestly, i have heard all of those same things straight from the Hanna tech support guy. The only thing that i didn't hear/do was put both probes in the calibration solution for about a hour...i only put the ph probe in there. I'll give it another try when i have grown my current seedlings out to take some clones. I abandoned the hydro attempt when i couldn't get the meter to work. I seriously want to return this meter and get something that is easier to use, because it is just a P.I.T.A. to hold both probes steady and at the right hieght in the water to get an accurate reading. Thanks again.

solarz

 

[Lemmongrass]

maybe your solution isnt stable and the acids are still forming salts with your nutes?

 

[mntnvew]

I have this same meter and THANK DAMNESS I found this site, I was searching and search for a way to get this thing to quit flashing 0.00 for hours!

Anways, what is everyones thoughts on using TDS Calibration Solution with this monitor? Is it required?

I am going to soak mine tonight and try to get it going as well as pick up so styrofoam to make a float for the probes.

THANKS ALL!!!!