Neptune Aquatics

PH and other probes

Scarbird

Scarbird

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Can anyone comment on the accuracy and reliability of PH probes?
I currently own the milwakee SM 102 and the PH-0007 waterproof pen type ph meter. Both are on the shelf, not being used.
Neither were reliable enough to eliminate the salifert test kit. Comparing colors is not my strong point either.
It's been a couple years, maybe the technology has improved.
I am considering a DA ph probe and module to go with my reefkeeper lite.
Any advice would be appreciated.
 
With all hand held meters, you want to calibrate prior to every use, especially the pens. If they have been stored too long and the bulb has been allowed to dry out, they are no longer any good :(

You should find the DA pH probe is accurate enough for you :)

FWIW the facility I work at has a TON of pH probes in use, and a ton of meters. We never use reagents for pH testing and we need to be very accurate with our pH.
 
Agree, calibrating those pens is critical.
But be very wary of off-brand or old reference solutions!
A good article on how far off they can be is here:
http://www.reefkeeping.com/issues/2005-02/rhf/index.php
See table 1.

Also : They may or may not be dead after being dried out.
If you soak them in hot 4.0 buffer solution, they often work fine.
(Start out hot, then soak for a couple of days)
afterward, if measurement stabilizes < 1 minute, you are probably good to go.
 
BAYMAC said:
With all hand held meters, you want to calibrate prior to every use, especially the pens. If they have been stored too long and the bulb has been allowed to dry out, they are no longer any good :(

You should find the DA pH probe is accurate enough for you :)

FWIW the facility I work at has a TON of pH probes in use, and a ton of meters. We never use reagents for pH testing and we need to be very accurate with our pH.
Click to expand...

So the idea of leaving the ph probe attached to the controller and the probe installed in sump doesn't work?
Meaning each time I want to take a reading I need to remove the probe from the sump, recalibrate, and then take a reading?
 
Scarbird said:
BAYMAC said:
With all hand held meters, you want to calibrate prior to every use, especially the pens. If they have been stored too long and the bulb has been allowed to dry out, they are no longer any good :(

You should find the DA pH probe is accurate enough for you :)

FWIW the facility I work at has a TON of pH probes in use, and a ton of meters. We never use reagents for pH testing and we need to be very accurate with our pH.
Click to expand...

So the idea of leaving the ph probe attached to the controller and the probe installed in sump doesn't work?
Meaning each time I want to take a reading I need to remove the probe from the sump, recalibrate, and then take a reading?
Click to expand...

No, just "hand held meters" and "pens", not units that are meant to run in liquids constantly, like controllers.

For those, I suggest a monthly cleaning and calibration. We do ours ever other week, but we have a much great issue with growth and precipitation on them then an aquarium would have.
 
rygh said:
Agree, calibrating those pens is critical.
But be very wary of off-brand or old reference solutions!
A good article on how far off they can be is here:
http://www.reefkeeping.com/issues/2005-02/rhf/index.php
See table 1.

Also : They may or may not be dead after being dried out.
If you soak them in hot 4.0 buffer solution, they often work fine.
(Start out hot, then soak for a couple of days)
afterward, if measurement stabilizes < 1 minute, you are probably good to go.
Click to expand...

We just make our own since we use so much, but given its so darn easy to make, I have never had issues with any brand I have used to calibrate. What would an off brand be in this case anyways?

IME nearly every time they dry out, they are dead. I don't bother with it any longer, my time is more valuable.
 
>What would an off brand be in this case anyways?
They did not say in the article, so I have no idea there.
I personally had an issue with a LFS bottle that simply said 7.0 Buffer Solution. No name.
Fortunately, it is fairly obvious if you calibrate and see some huge PH shift.
The danger is being a bit off, and deciding to tweak your PH, instead of questioning the measurement.

> IME nearly every time they dry out, they are dead. I don't bother with it any longer, my time is more valuable.
Yep, time/money tradeoff.
If you have a $150 Hanna ph/orp pen : probably worth a quick try.
 
If you are foolish enough to buy a Hanna pen in the first place :lol: I was one of the fools, once :(

Ahh, I know which bottle that is, its not even an off brand, just a poor job of the manufacturer of marketing their product :lol: Ugh :( (It's also not legal for sale packaging)

I don't know of any off brand "aquarium" related fluids, well, unless you want to call PinPoint off brand, then I'd agree.
 
I have a PinPoint probe and a DA probe in my sumps I use with a Digital Aquatics SL1 (and SL2) controller. As long as I keep it clean each month (I gently use a soft bristle toothbrush) and calibrate it every couple of months with the pinpoint calibration fluids (7.0 and 10.0 ) [adjusted for temp], it seems to be fine for seeing the general daily fluctuation of the tank as well as any major changes in pH caused by a dosing accident. I am happy with mine it is always agrees within ~0.1 or so with my ELOS pH test kit. Again, as a constant pH monitor in the sump looking at general ballpark pH and looking at the relative swings they both work fine.
 
Thanks everyone,
I suppose I will go forward with the DA ph probe and pay attention to the maintenance tips.
Baymac can you provide info on making calibration fluids?
John
 
Its not worth it for you to make your own given the shelf life. If I were you, i'd buy a box of each of the two needed ones from Hanna or Milwaukee. The packets are single use so there is no shelf life issue.

If you really want how to make it, I will talk to the scientist on Monday.
 
BAYMAC said:
Its not worth it for you to make your own given the shelf life. If I were you, i'd buy a box of each of the two needed ones from Hanna or Milwaukee. The packets are single use so there is no shelf life issue.

If you really want how to make it, I will talk to the scientist on Monday.
Click to expand...
I guess I'll just buy packets, but thanks. Is it true that certain household products have specific ph values? I suppose a person could use these to verify calibratiion at random intervals. Any feedback on these products?
 
using a semi known pH of a solution to verify something designed as a calibration is a wee bit backwards. By the nature of buffered solutions, the standard will be far more reliable than your household solution. Stick with calibration packets. They are cheap and won't poison your probe.
 
I wouldn't know which products would be stable/constant enough for me to use them as a calibration. I'm sure there are, I just don't know of any :)

We shoot for certain pH's in our products, and I know most other manufacturers making feeds worry about pH as its one of the best methods to help preserve a feed.
 
OK, I think I got it.
How about salinity probes and the others. Any feedback on the neccesity or accuracy of the other probes?
I know PH is huge for obvious reasons, but with a controller and network interface, it would be nice to see different parameters from vacation. Which are recommended?
 
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