pH probe erratic readings

Bruce60

Active Member
View Badges
Joined
Oct 28, 2018
Messages
135
Reaction score
182
Location
Bloomsburg, PA
I had noticed my 2 year old pH probe started acting glitchy despite recalibration, so I went and replaced it with a new probe. I was able to calibrate the probe and confirmed that it was reading both the 7 and 10 pH standards accurately. After a few days, the probe started with the same erratic readings (see image). Nothing was added to the tank at 1 am to cause the spike in pH. Measurements made yesterday were Alk=9.8, Ca=415, Mg=1260. Temp ranges between 77.5 and 78.3 F, salt between 33.3 and 33.4, and ORP between 390-400 in the past days. Any thoughts on the issue? Is this a problem with the Apex unit instead of the probe? How do I go about resolving this matter? Thanks!
Screen Shot 2021-02-22 at 8.54.17 AM.jpg
 

rkpetersen

walked the sand with the crustaceans
View Badges
Joined
Sep 14, 2017
Messages
4,481
Reaction score
8,602
Location
Near Seattle
I've seen rapid transients like this in both pH and ORP probes from a small snail traversing the electrode.
Seems unlikely to be an Apex malfunction, with it reading as expected most of the time.
Do you have an alarm notification on your phone for when the pH does this?
If so, you can look at the probe while it's happening, maybe catch a critter in the act.
 
OP
Bruce60

Bruce60

Active Member
View Badges
Joined
Oct 28, 2018
Messages
135
Reaction score
182
Location
Bloomsburg, PA
I've seen rapid transients like this in both pH and ORP probes from a small snail traversing the electrode.
Seems unlikely to be an Apex malfunction, with it reading as expected most of the time.
Do you have an alarm notification on your phone for when the pH does this?
If so, you can look at the probe while it's happening, maybe catch a critter in the act.
Good thought, but the probe is in a part of the sump where there are no critters to get on the probe. One idea I heard is that transient air bubbles could also be a cause.

I figured that I am going to watch and wait. I might check the probe calibration by testing it in fresh pH 7 and 10 solutions. Thanks!
 

rkpetersen

walked the sand with the crustaceans
View Badges
Joined
Sep 14, 2017
Messages
4,481
Reaction score
8,602
Location
Near Seattle
Good thought, but the probe is in a part of the sump where there are no critters to get on the probe.

Mine are in my return chamber, and I once thought that as well. :D
 

What are you most excited to read about in our REEF OF THE MONTH articles?

  • I love reading about reef equipment!

    Votes: 17 6.3%
  • For me, it's all about the CORALS!!

    Votes: 27 10.0%
  • Seeing and reading about cool fish that I wish I could keep!

    Votes: 6 2.2%
  • Looking for neat innovations and creative solutions they're using!

    Votes: 52 19.2%
  • Looking mostly for stuff I can try on my tank!

    Votes: 24 8.9%
  • Are you kidding?? I'm excited about ALL OF IT!!

    Votes: 145 53.5%

Online statistics

Members online
2,057
Guests online
5,489
Total visitors
7,546
TCK Corals
Top