Pinpoint PH Monitor

NaH20nerd · Jan 21, 2018

Has anyone had issues getting reliable readings from their Pinpoint PH Monitor? I am getting readings that seem way too low. 7.51 where my API test kit shows 8.1-8.2. It calibrates correctly which has me scratching my head. Corals and fish seem to be fine...but I would like to know for sure.

I have been dosing BRS 2-part in an effort to maintain KH and Calcium. Wondering if this will affect my test results with either API or Pinpoint. Any info on this matter will be greatly appreciated.

[Cameron] · Jan 22, 2018

All monitors can go "off" and test kits can read poorly so either could be "wrong". Pinpoint is a solid monitor so if there is a problem with it, it is probably the probe.

Randy Holmes-Farley · Jan 22, 2018

How did you calibrate it, and did you check that it reads both calibration fluids correctly after calibration?

Randy Holmes-Farley · Jan 22, 2018

NaH20nerd said:
I have been dosing BRS 2-part in an effort to maintain KH and Calcium. Wondering if this will affect my test results with either API or Pinpoint. Any info on this matter will be greatly appreciated.

Nothing you could add at a reasonable dose will interfere with a pH measurement.

NaH20nerd · Jan 22, 2018

Randy Holmes-Farley said:
How did you calibrate it, and did you check that it reads both calibration fluids correctly after calibration?

Yes. I used calibration solution 7.0 and 10.01 from Aspera.

NaH20nerd · Jan 22, 2018

[Cameron] said:
All monitors can go "off" and test kits can read poorly so either could be "wrong". Pinpoint is a solid monitor so if there is a problem with it, it is probably the probe.

Can I use any probe with the Pinpoint or only Pinpoint probes? But if it calibrates correctly I should assume that it’s correct right?!

Chris Villalobos · Jan 22, 2018

I'm in the same boat. I'm giving my pinpoint ph monitor one last try with a brand new probe, but if it still won't calibrate I'm just going to use drip tests and stop wasting my time with expensive probes that go out of calibration way too often. It's not like I'm running a calcium reactor.

Randy Holmes-Farley · Jan 22, 2018

NaH20nerd said:
Can I use any probe with the Pinpoint or only Pinpoint probes? But if it calibrates correctly I should assume that it’s correct right?!

yes, any probe that connects will work, and if it calibrates correctly and reads the solutions after the fact correctly, it is good to go.

Maybe the solutions themselves are off. The 10 especially goes bad as it ages, although that leads to high and not lower pH than expected.

Randy Holmes-Farley · Jan 22, 2018

FWIW, the Pinpoint pH meter is susceptible to electrical interference. Measure pH in a cup away from the tank to reduce that concern.

bubbaque · Jan 22, 2018

My pin point gives me low readings also, 7.65 at the lowest and 7.85 for the high. I was calibrating it every week but it always seem to be calibrated. I just stopped paying attention to it since my corals grow fine.

cumbeje · Jan 22, 2018

If you re calibrate the probe and it is still drifting. Two things that could be needed. First if you are using a battery replace that first. Second if battery is not working than time for a new probe. I usually get roughly about a year out of probes but results vary.

bubbaque · Jan 22, 2018

I just went and tried the tank water in a cup and it read the same. My display is plumbed to a frag tank outside sohalf the water is exposed to outside air. I have no idea how my ph is so low.

NaH20nerd · Jan 22, 2018

I checked calibration again tonight...away from the tank. Dead Nut perfect on both 7.0 and 10.01.
Checked PH of water (away from tank) and 8.00 is the result. Not what I was expecting for a PM test but not low enough to worry about I suppose. I’m going to assume these are correct readings. My 2nd assumption is that I just have a low PH due to low oxygenation in the tank.

Thinking about upgrading to a IM Nuvo Fusion 40 gallon.

Bruce Burnett · Jan 23, 2018

Randy Holmes-Farley said:
FWIW, the Pinpoint pH meter is susceptible to electrical interference. Measure pH in a cup away from the tank to reduce that concern.

Yes they are prone to interference, I replace two wave pump power supplies which fixed mine as it was giving low readings. low quality power supplies on leds will also cause same problem. I prefer the Milwaukee double junction probe over the Pin Point as it seems to give a more reliable reading.

Forsaken77 · Jan 25, 2018

NaH20nerd said:
Can I use any probe with the Pinpoint or only Pinpoint probes? But if it calibrates correctly I should assume that it’s correct right?!

Are you using double junction probes? I have the Milwaukee Ph monitors and replace the probes with double junction, non-Milwaukee probes. Though the Milwaukee brand lasts longer. As long as it has the same connection, you can use any probe. I use the Pinpoint Temp Controller and it's definitely spot on. Make sure there isn't gunk build-up on the bottom of the probe, or trapped air bubbles.

Forsaken77 · Jan 25, 2018

Randy Holmes-Farley said:
yes, any probe that connects will work, and if it calibrates correctly and reads the solutions after the fact correctly, it is good to go.

Maybe the solutions themselves are off. The 10 especially goes bad as it ages, although that leads to high and not lower pH than expected.

Hey Randy... Will using the 7 & 4 Ph solutions dramatically shift the readings? Because I use the Milwaukee monitors (not controllers) and even for the saltwater monitor they say to use 7 & 4. I usually calibrate using all three, 7, 4 & 10, but didn't know the 10 goes bad. It's about 1.5 years old, the bottle of Milwaukee 10. So if I assume the 10 is bad, will 7 & 4 suffice?