Faulty Neptune pH probe

[bluemon]

I've owned this thing for a while, probably 6+ years

Just a few days ago, while doing my routine water change, my probe got exposed to air, as it does during all my water changes. However, this time I also took apart my filter roller to clean that up.

It comfortably always read 8.3-8.5 for my pH, which I took at face value since that seemed healthy and I usually don't chase pH.

Now after the water change, it reads 7.2-7.4.

I tested the pH with two test kits, one paper and one Salifert, both registering at around 8.3 pH.

I know these aren't the most reliable things, but I did try some troubleshooting I found online like:

disconnecting from Apex, rebooting, reconnecting and recalibrating

or

cleaning the meter with acid and recalibrating.

Both of which results in the same 7.2-7.4 range.

Is there something else I should be trying or is it time to get another probe?

Also the livestock look fine and the ALK is at 9.1 so the pH is probably correct at 8.3

 

[Justdrew]

It's my understanding the pH probes only last 2-3 years. They become more difficult to calibrate.

 

[Tangdora]

Do you have an extra 7.0 packet lying around that you drop it in to see how off it is after sitting for a few mins. Also do you calibrate it using the fusion app or .local

 

[Ryan - Serious Reefs]

Before you recalibrate put it in one of the calibration solutions and test to see if it is reading accurately. If not then recalibrate. If it doesn’t hold calibration replace it.

12-18 months is pretty common usable life for a probe submerged in salt water. 2-3 years would be awesome. 5+ years is a miracle:)

 

[bluemon]

Do you have an extra 7.0 packet lying around that you drop it in to see how off it is after sitting for a few mins. Also do you calibrate it using the fusion app or .local

I do, I shall try that. I am using the fusion app. Did not realize .local even had that function.

Before you recalibrate put it in one of the calibration solutions and test to see if it is reading accurately. If not then recalibrate. If it doesn’t hold calibration replace it.

12-18 months is pretty common usable life for a probe submerged in salt water. 2-3 years would be awesome. 5+ years is a miracle:)

Yea, might be time to replace them.

My salinity probe is at least 5+ years too and ORP must be closing in on 10+.:face-in-clouds:

 

[bluemon]

Well bad (?) news is that it registers the 7 calibration fluid as pH 7. Maybe the scaling is off for it? Not sure. Probably just a new probe in my future

 

[Tangdora]

did the water level increase after your water change? Don’t know why, but I seem to notice on mine at least the pH changes sometimes just dropping it 1 inch lower into the water or even raising for that matter