Hanna calibration kits

[Myka]

Has anyone tried out the Hanna calibration kits for the Hanna Checkers? Before I go ahead and order a couple, I'd like to hear if they seem to work ok.

I don't think my HI713 PO4 Checker is reading accurately, so I would like to confirm, and I may as well check my HI755 Alkalinity Checker while I'm at it.

[Reef Pilot]

Originally Posted by Myka

I don't think my HI713 PO4 Checker is reading accurately, so I would like to confirm, and I may as well check my HI755 Alkalinity Checker while I'm at it.

Does your 3:00 minute timer come on after pressing C2?

[DSlater]

Do you feel your PO4 readings are high, low, or just inaccurate?

My HI713 always gave higher readings but consistent so I never really questioned. Finally checked against another kit and it was reading way high. Tried my next box of reagent and everything tested at 0.00ppm. Even tap water and rejected water from RODI.

I went back to Hanna support with a couple questions and this was their response. Not designed for salt water and non-repairable.

"Hello,
The HI 713 is not designed to test salt water but fresh water.
I’m not sure what kind of readings should be expected with RO/DI water, but if the readings are constantly high even with fresh water, you might look at cuvet condition or dirt in the optical cell that could be interfering.
It would be also possible to test the instrument with HI 713-11 which is a CalCheck standard kit used to test the accuracy of the instrument. Have you tried another lot of reagents to see if it would make a difference?

As the warranty on these Checkers is 6 months, this meter could not be covered under warranty, and in the case it would really be faulty, such instruments are not repairable and simply needs to be replaced.

Regards

François Coulombe
Spécialiste au support technique / Technical support specialist
Hanna Instruments Canada Inc.
1-800-842-6629"

[Myka]

Originally Posted by Reef Pilot

Does your 3:00 minute timer come on after pressing C2?

Yes.

Originally Posted by DSlater

Do you feel your PO4 readings are high, low, or just inaccurate?

The readings are unusually low.

Originally Posted by DSlater

"Hello,
The HI 713 is not designed to test salt water but fresh water.

Well that is certainly interesting. I checked on various online vendors and every vendor I checked listed the HI713 as marine and freshwater. I checked the Hanna Instruments website and indeed there is no mention of marine use where the HI736 phosphorus checker does mention marine use. That is something else altogether!

[DSlater]

I went back to Hanna and asked about the marine use, should hear tomorrow.

The reagent lot that was giving me 0.00 readings on everything (salt and fresh) was Lot #H075. Others people have no issues with this lot# though.

[Reef Pilot]

Originally Posted by DSlater

Do you feel your PO4 readings are high, low, or just inaccurate?

My HI713 always gave higher readings but consistent so I never really questioned. Finally checked against another kit and it was reading way high. Tried my next box of reagent and everything tested at 0.00ppm. Even tap water and rejected water from RODI.

The color test kits will always read zero before the Hanna. They are simply not as accurate at the ultra low range. That's why I got the Hanna.

Some have had difficulties getting accurate and consistent readings from their Hanna Checker. These include not pressing AND holding after C2 until the 3:00 min timer shows on the display. Not using the same vial for both the C1 and C2. Not cleaning all fingerprints. Not getting all the powder out (there are tricks to this). Not mixing properly (you have 3 min and you need to pause to let all fine bubbles dissipate).

Have not seen problems with reagents, but I guess that is possible.

I have been using mine for a couple years now, and it has been very accurate and totally consistent with the readings. I have also personally helped others who have come to my place with their checkers to get theirs working accurately. And have that offer open to anyone else that might be having problems with theirs. Sometimes the issues are not apparent until you see how a person does their testing (many ways to do it wrong).

[Myka]

I sent an email to Hanna asking about both the HI713 and HI736 checkers. I did some searching on Reef Central and Google and didn't see this fw/sw Issue mentioned.

Originally Posted by Reef Pilot

Sometimes the issues are not apparent until you see how a person does their testing (many ways to do it wrong).

Yes. Good point.

[davej]

Picked up a set to check my low range phosphate checker. Read exactly 1.00 like it should have. Good to know it's working right.

[Myka]

Originally Posted by davej

Picked up a set to check my low range phosphate checker. Read exactly 1.00 like it should have. Good to know it's working right.

Awesome, thanks!

[Myka]

I emailed tech@hannainst.com and here is the response I got:

Originally Posted by Pete

You can use the HI713 on both fresh and salt water samples.

The HI713 meters accuracy is +/-.04 + +/-4% of reading.

For example:

0ppm the accuracy is +/-.04

1ppm the accuracy is +/-.08

2ppm the accuracy is +/-.12


If you are looking for a more precise measurement you should consider using the HI736 Phosphorus Ultra Low Range meter.

This meter +/-5ppb + +/-5% of reading


This meters range is from 0 to 200 ppb (.20ppm) of Phosphorus. You would just have to do some conversion to get the reading into ppm of PO4.

To convert the phosphorus (P) reading on this meter in to phosphate (PO4) you would have to multiply by .003


For example:

Meter reads:
10ppb of P = .03ppm PO4
100ppb = .30ppm PO4
200ppb = .60ppm PO4


Regards,
Pete