What makes a pH probe good for hobbyists?

[Miami Reef]

There are many types of pH probes on the market.

Hanna probes, double junction, single junction, cheaper Amazon probes, and a bunch of other types and brands.

What makes a probe accurate enough for reef tanks?

The difference between single junctions vs double junction probes is the latter has the inner silver reference junction encased within another junction, usually containing a mostly potassium chloride solution. This apparently helps prevent metals and protein from coming in direct contact with the silver and forming precipitates, potentially leading to inaccuracies overtime.

At least that’s my interpretation of what BRS mentions: https://www.bulkreefsupply.com/brs-double-junction-lab-grade-ph-probe.html



I like sustainability, practicality, and being reasonable. The exact precision of the probe by 0.01 doesn’t make all that big of a difference for reef tanks. The ocean and tank’s pH are naturally variable, and it just isn’t 100% required to get that sort of accuracy for a pH measurement to be useful IMO.

The bare minimum, in my opinion, is that a probe should have a two-point calibration within the range of what you’re trying to measure.

So, what makes a probe good enough for hobbyists?

 

[Miami Reef]

I personally use the double junction probe.

 

[bubbgee]

I have two pH probes connected to Apex. Both have been calibrated and they are off by 0.1 in the same area of the tank (basically next to each other). I used a Hanna pH probe as well (and that is even worse that I stopped using it completely).

At this point, I gave up chasing the exact number and am going with the range. As long as the probe does not hit 7.6, I will be happy. I adjusted my kalk and 2-part dosing to that setup and maintaining 7.8 to 8.4 range (as far as Apex thinks it is).

 

[bluemon]

Honestly for me, i don't trust the pH probe that much.

Maybe that's because I replaced it 2 times in the span of 15 years despite it being questionable at times...

So I think for me the price would have to be my #1 priority, with the addendum that I am willing to replace it a lot more frequently, maybe once a year. I don't think many probes are made to last long anyways in the way us hobbyists are using it; that is in turbid waters (leading to air pockets), filled with creatures that like to use the probe casing as a refuge, submerged 24/7.

That is in contrast to the pH meter in my CaRx, which definitely lasts much longer.

So mostly, I just use the delta of the PH from the probe, rather than the absolute pH. If the pH probe usually reads 8.0 but appears to be 7.6 one day, I'll do some digging, but I don't 100% trust that my pH is ACTUALLY 8.0

 

[X-37B]

Like other testing equipment have a backup.
I like and use the brs DJ Probe.
I have 3 hand held meters so I can check with another if needed.
Single junction probes can take awhile for ph to settle on a number while DJ probes give virtually instant results.
I have an old hanna meter and probe that's as accurate as my others but it takes 3-4 minutes to settle on a number.

 

[FishLvR]

Like other testing equipment have a backup.
I like and use the brs DJ Probe.
I have 3 hand held meters so I can check with another if needed.
Single junction probes can take awhile for ph to settle on a number while DJ probes give virtually instant results.
I have an old hanna meter and probe that's as accurate as my others but it takes 3-4 minutes to settle on a number.

Can you link me to this. My handheld sucks.

 

[Randy Holmes-Farley Verified Community Expert]

Refillable is good for a lab, but maybe bad for a reefer who drops it too deep and gets seawater in it if the hole is not fully plugged.

Double junction is good.

Plastic barrel reduces breakage.