Can anything interfere with getting an accurate pinpoint ph reading?

glb · May 12, 2016

I recently got a digital pinpoint (metallic electrode with glass globe surrounding it) continous ph monitor. I calibrated it with the calibrating solutions I received and mounted it in the tank. My tank has usually run a lowish ph 7.8-8.0. With the new monitor, it's running 8.2-8.4. Normally I'd say that's great but I'm a little suspicious of the readings. When it read 8.2 yesterday ran a salifert ph test to double check and it was about the same. Here's my question. Can magnets or electrical wiring knock these things out of whack? My ato holder is close to it and its held in place by a really strong magnet. Do I need to keep it away from magnets or other electrical wires? I've never run a continuous monitor so want to make sure the readings are reliable.

glb · May 12, 2016

Bump. I'd really appreciate your input!

redfishbluefish · May 12, 2016

You can get electrical interference of pH probes, but my experience is that it typically dances around, and will not produce a constant pH. I'm trying to remember what piece of equipment I had that screwed up my pH readings....I'll have to think for awhile.

Just to make sure, you calibrated with both pH 7 and pH 10 fluids?

The other point about pH probes is that you never want to completely submerge the probe...it will ruin the probe.

glb · May 12, 2016

redfishbluefish said:
You can get electrical interference of pH probes, but my experience is that it typically dances around, and will not produce a constant pH. I'm trying to remember what piece of equipment I had that screwed up my pH readings....I'll have to think for awhile.

Just to make sure, you calibrated with both pH 7 and pH 10 fluids?

The other point about pH probes is that you never want to completely submerge the probe...it will ruin the probe.

I used the 4 and 7 fluids that came with it. The only part that's submerged is the bottom inch of the probe, where the glass sphere is. That part is submerged all the time but the rest is out of the water.

Salty1962 · May 12, 2016

As @redfishbluefish stated electromagnetic and electrostatic devices can interfere with PH probes. I know of a few people who have had issues with the Pinpoint PH reader. It's not designed to be in constant use and you have to calibrate it frequently. For saltwater, you should use 7&10 for calibrating ph probes. I know this is not what you want to hear but it's worth noting.

glb · May 12, 2016

This is what I bought. It says continuous on it. What do you all think?
http://www.amazon.com/gp/aw/d/B00MG...r+aquarium&dpPl=1&dpID=41Sp5UYYcfL&ref=plSrch

glb · May 12, 2016

Ok i just got 7 and 10 at the lfs

glb · May 12, 2016

So do you go back and forth between the 2 calibration solutions? Dip in RODI in between until both numbers match?

redfishbluefish · May 12, 2016

Read the manual! And yes, you will want to put the probe into each of the calibration solutions and adjust the meter to read either 7 or 10. Rinse well between each solution with RO/DI.

glb · May 12, 2016

redfishbluefish said:
Read the manual! And yes, you will want to put the probe into each of the calibration solutions and adjust the meter to read either 7 or 10. Rinse well between each solution with RO/DI.

Thanks. I did read the manual but i think it was originally in Chinese. You get the point.

redfishbluefish · May 12, 2016

glb said:
Thanks. I did read the manual but i think it was originally in Chinese. You get the point.

是 (shi)!!!

Looking at the Amazon link, it looks like you need to use the little screwdriver to make adjustments. What you need to decipher from the manual is the order of the calibration fluids (or maybe it doesn't matter).

glb · May 12, 2016

redfishbluefish said:
是 (shi)!!!

Looking at the Amazon link, it looks like you need to use the little screwdriver to make adjustments. What you need to decipher from the manual is the order of the calibration fluids (or maybe it doesn't matter).

I watched a few youtube videos and figured it out. Using the 7 and 10 made all the difference in the world. Now the ph is sitting at 8.0, which is where it usually was.