pH probe with transparent gel formation on sensor.

[A. Grandis]

Further, bacteria will coat just about anything int eh tank, even if that wasn't its origin.

FWIW, I've never seen or heard of this happening.

The gel is nowhere else in the system that you can see?

I though I've seen some on the ORP probe, but took a closer look and there is nothing there.
I had similar gel formation in the past on another Pinpoint pH probe, but not as thick.

Tank is 6+ year old. No, the gel nowhere else in the system, as far as I can see.
I've got many types of inverts on my artificial rocks introduced with natural water through the years, like sponges, snails, hydroids, worms, etc...
Sand is thin, oolitic sugar size aragonite, about an inch to inch 1/2 high. No signs of bacterial films on/in the sand at all. System is well fed and clean, algae free, with healthy organisms.

I'm still trying to connect the chemistry around the glass bulb attracting that specific bacteria and allowing a perfect environment for it.
Indeed very interesting.

I've contacted Milwaukee about that to see what they think, but they didn't reply yet.
I was thinking to purchase the new pH monitor from Milwaukee and see what happens.

I'll keep you posted.:thumbsup:

Grandis.

 

[A. Grandis]

FWIW, I have this exact same yellow probe and mine grows a similar goop, though not as fast and it's a pink color. None of my other probes are so affected, although this was the only one in the dark. Since I moved it to a lighted spot no goop.

That's very interesting! My probe is in the sump, and it's dark also. Not completely dark though.
Hummm...
Pics please?

Grandis.

 

[ca1ore]

No goop to take a picture of, sorry. The other thing I did was to install this probe into the recirculation stream of my calcium reactor and the strong flow around the tip also helps to keep it clean.

 

[A. Grandis]

Thanks ca1ore!
I'll see what I can try here.

Please keep your ideas coming...

Grandis.

 

[A. Grandis]

Ok, I still didn't change the probe around...

The answer from Milwaukee was that " Seal has gone out...".
Therefore I'm assuming the gel indeed comes from inside of the probe and the bacteria seen in the gel is evidently just taking advantage of the substance to grow in/on it.
They suggested to get a new probe (MA911B/2).

Grandis.

 

[Randy Holmes-Farley]

They suggested to get a new probe (MA911B/2).

Make sense to me, and convenient for them as well.

 

[A. Grandis]

Make sense to me, and convenient for them as well.

Yep, I think they like that! :thumbsup:
But the probe was working for so many years too... Time to change it.
Thanks again for the help Randy! Thanks to all.
If the new probe develops the gel around the bulb that probably wasn't the case, unless the new one also has the same problem with the seal.
We'll see...

Grandis.

 

[Randy Holmes-Farley]

:thumbsup:

Happy Reefing.

 

[A. Grandis]

Alright...
Left the probes alone for a while and guess what?

The yellow probe on the left is for ORP.
The pH probe is on the right with a bigger gel structure.
Both have the gel!
It must be bacteria.
The picture doesn't lie...
The black probes are for the ReefKeeper. No gel. Go figure! :frog:

Grandis.

 

[Randy Holmes-Farley]

Curious.

 

[vette.tech]

Seems just like the bacteria I get in my salt mixing container if I let it sit for a couple days, though the reason why it forms on the probes is indeed peeking curiosity

 

[A. Grandis]

Just really specific right there. Must have something to do with the micro environment around the bulb.
I'm waiting for Randy to let us know why...

Grandis.

 

[Randy Holmes-Farley]

Just really specific right there. Must have something to do with the micro environment around the bulb.
I'm waiting for Randy to let us know why...

You'll have to keep waiting.

 

[A. Grandis]

:thumbsup:

 

[A. Grandis]

Update:
I've got the probe running in another system for 2 weeks+ and the gel didn't develop.
During transfer I allowed the probe to dry fro about 6 hours and calibrated afterwards in order to make sure the bacteria wouldn't be transferred from system to system.

New Milwaukee probe and monitor was installed on the 75gal system.
No more gel in both systems and readings are showing normal ranges.
Go figure!

Grandis.

 

[Randy Holmes-Farley]

I'm glad it is working well!

 

[A. Grandis]

Up to this date that gel structure never formed again.
The system is running all this time without any pH probe problems.
Go figure!
Grandis.

 

[Jonesrd1]

Hi, in my experience with pH electrodes it is the difference between agarose gel (which bacteria "eat") vs. acrylamide gel (which they don't). I have seen this gell formation many times over the years. We now use acrylamide exclusively in our chemistry teaching labs.

 

[A. Grandis]

That's god info!
Do you know why the gel forms? Is that a leak?
Grandis.

 

[Jonesrd1]

The reference part of the electrode has a controlled leak called a reference junction that connects the KCl inner gel to solution being tested, in your case the seawater. So by definition all pH electrode are leaky and if the solution they leak is bacteria food poof bacterial gel. There is some good information to be found on a google search for "glass electrode". Just finished this with some seniors from Instrumental lab, it was a lot of fun using your post as a real world example. Thanks