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this is me
06/01/2012, 04:14 PM
Got this probe when I bought my Profilux III3ex pack. It's supposed to be a lab grade. It's been running well but for the past month, it was swinging like crazy. I re-calibrate and it'll work for a couple days. I finally pulled out the probe today and notice there's some rust on the wiring. I'm guessing something is loose from the wire to the probe itself.
This is less than 8months old!

Probes placement to show where the water level is
http://www.pbase.com/image/143709518/original.jpg

Whole Probe
http://www.pbase.com/image/143709413/original.jpg

Close up at the rust
http://www.pbase.com/nicksreef/image/143709415/original.jpg

AQD_ottawa
06/02/2012, 02:03 PM
Yep, you got the top wet so its rusted, NO probe is water proof past the cable inlet, if it is submerged this is the result.

Every probe is like this.

When a main pump is turned off the sump level rises and the probe gets submerged if you have not adjusted your probe height to take this into account.

this is me
06/02/2012, 03:54 PM
So what happen during a water change the water level goes down and the probe is exposed to air? Is this an issue also?
I've been in this hobby for almost ten years and been through only 3 PH probes. My set up has always been this way and I've NEVER seen a rusted probe.
If the GHL can not handle being submerged, then I suggest putting a marking "Max water level" and draw a line on the probe.

AQD_ottawa
06/02/2012, 04:19 PM
Hi Nick

A probe during a water change is no issue, it takes a long time for a cell to dry out.

If other probes you have had have used copper wire which is quite detrimental in its own way then you would not see them rusting or simply have been lucky.

The GHL probes are genuine lab grade they all come with certificates there is no concern over quality at all, however they do need the correct care.

All probe manufacturers are the same, this is not unique and no other company puts lines on them, also remember not one pH probe is made specifically for the reefing world they all come from generic useage mainly lab use where submersion is not really an occurance. This includes GHL probes that are made by a German manufacturer of precision electrodes.

Specific submersible probes are made but they do come with a cost factor

http://www.omega.com/pptst/PHE-6510.html
PHE-6510-GL 5 $315.00 Submersion pH electrode with ground loop

I am sorry you have had this issue, but its good advise for everyone really.

By drying your probe for a week in a warm place (keeping the tip moist) you may find it recovers.

this is me
06/06/2012, 08:03 AM
I completely disagree with your response!
All the probe need is a dab of silicone where the line is coming out to avoid moisture getting in there. I have 3 GHL probes in the same place and only the PH probe is doing this. If you take a closer look at the temperature probe(middle probe in the first picture), you can actually see there's a dab of silicone-like. Why isn't this on the PH probe and everything else but only on the temperature probe.
This is not rocket science. C'mon!
My previous PH probes usually die from old-age and dried out cell, not due to rusting. I can guarantee you that most people don't encounter this problem with other probes.

AQD_ottawa
06/06/2012, 08:14 AM
Hi Nick,

I respect you 100% as one of our foremost dedicated users, but I am not going to carry this dilaogue on here on this forum, if you have an issue with the what is the industry standard as clearly shown here then please email.

We or GHL do not have the capacity to change industry, I am sure you understand that the manufacturers for GHL are not going to change something for what is probably less than 10% of their market share. I also have personally researched many times supposed fully submersible probes at a lesser value than shown above and they all eventually have let go. If a dab of silicon was a viable relaible option I think all manufacturers would be jumping on it instead of offering submersible options at over $300.

if you want a 100% submersible probe I have provided a link above for you to purchase from.

As above I do not wish this to continue here its not what the forum is for so respectfully I ask you to email me at sales@aqua-digital.com

The temp probe is also NOT fully submersible, please do not assume from what you see it is.