It’s almost 20 years since I purchased my first Hanna Photometer.  In those days it was Hanna’s ‘C203 Multiparameter Ion Specific Meter for Aquaculture’ that had become the ‘go to’ meter for those wishing to venture into the world of ‘digital’ water parameter testing.  If memory serves me right it used to cost around £400 at the time.

Hanna C203

Hanna C203

The equivalent, if somewhat more advanced, model in Hanna’s current line up would be the ‘HI-83303-02 AquaCulture Multi-parameter Photometer with pH Meter’, it measures all the C203 did, and more, for the price of £750.

Hanna HI83303

Hanna HI83303

In reality, the vast majority of Koi keepers cannot warrant the price of a £750 water testing meter, a meter which is capable of doing vastly more than they would ever require.

Thankfully Hanna Instruments make a range of much more pocket friendly single parameter photometers, aptly named ‘Pocket Checkers’, more for their size than their price.

Hanna Pocket Checker, fits in the palm of your hand, and probably your pocket

Hanna Pocket Checker, fits in the palm of your hand, and probably your pocket

I first purchased the low range Ammonia and Nitrite Checker units back in September 2019 having become completely disappointed with ‘manual’ drop and tablet kits from a number of suppliers.  For whatever reason I never actually got as far putting a battery in them (they come supplied with a single AAA battery that’s required to run them).  In fact I think that was largely the problem, getting the battery cover off requires seemingly more effort than it should do due to a connector block fitted to the battery cover.  Not only are you removing the cover you are also disconnecting the connector block at the same time, and there is nothing really to hold onto to separate them.  The units ended up on the shelf, winter came, everything was running fine, the indoor tank here had the Seneye installed (http://nishikigoi.life/2019/12/17/seneye-a-review/) and I’d been given a set of JBL tests which are actually the best drop test kits I’ve ever used.

With new systems to start up and cycle here a couple of months back I decided it was time to try out the Hanna Checker units.  The fact that they are in regular use, and I’ve added the Total Chlorine ULR Checker unit as well, probably tells you my conclusions so far.


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In this article we’ll take a look at what ‘Pocket Checkers’ actually are, how they work and why they may be just what you are after if you are becoming frustrated with other test kits.

What are Hanna Pocket Checkers?

Hanna Instruments website describes them as, ‘Hanna Checkers are small, handheld photometers that provide higher result accuracy than typical chemical test kits.

Available in 34 models offering dedicated parameter testing, each model in the range offers users improved digital technology in a compact design with easy to follow instructions making measurement quick and hassle-free.’

Of the 34 models available, some which are specific for saltwater, it is those that test Ammonia, Nitrite which are likely of main interest to Koi keepers, along with perhaps the more specialised Chlorine, Phosphate and Alkalinity.

For all of these parameters there are further options with regards to the sensitivity of the device, for the purposes of Koi keepers the most sensitive of these units is the one to choose, the units I have and will be the subject of this review are:

Ammonia – HI-700 Ammonia Low Range Colorimeter – (0.00 to 3.00ppm)


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Nitrite – HI-707 Nitrite Low Range Handheld Colorimeter – (0 to 600ppb)

Chlorine – HI-761 Total Chlorine Ultra Low Range Handheld Colorimeter – (0 to 500 ppb)

Hanna Pocket Checkers

Hanna Pocket Checkers

How do Pocket Checkers work?

Essentially they work exactly the same as a normal test kit in that a reagent is added to a sample of water and allowed to react for a period of time for a colour change to occur (or not).  Of course the biggest issue with normal drop test kits is interpretation of any colour change and matching it against the colour card.  With the greatest will in the world this is never more than a guesstimate at best.  Sometimes it’s hard to work out where the colour can possibly come within the shades offered on the colour card.

The pocket checker removes this guesswork entirely by giving an ‘exact’ digital reading on the display after the allotted time has passed.  It does this by shining a light through the water sample to detect the colour change, something it can do with far more accuracy than the human eye can do, and far more accurately than comparing against a colour chart.

The actual process of taking a reading is a 4 step one for all parameters (taken from Hanna website).

4 steps to taking a reading

4 steps to taking a reading

 


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Different test kits have different kinds of reagents.  The ammonia test for example has 2 dropper bottles of liquid whereas the nitrite and chlorine tests have sachets of powder.

Different test kits also have different waiting times for the results.  Chlorine is completed in 2mins 30 seconds, Ammonia in 3mins 30 seconds, whilst Nitrite takes a full 15 minutes.

How much do they cost and what do you get?

All of the Hanna Pocket Checkers cost £76.38 (inc vat) if ordered directly from Hanna Instruments.  The exception to this is the ‘HI-701 Free Chlorine Handheld Colorimeter’ which is £51.96 (inc vat).

Each tester and accessories is supplied in a strong plastic storage box (which won’t fit in your pocket but does keep them safe and tidy).

Hanna Pocket Checker storage box

Hanna Pocket Checker storage box

Below we’ll look at what is included with each, and perhaps more importantly what the ongoing costs are of using the specific units.

Ammonia – HI-700 Ammonia Low Range Colorimeter – (0.00 to 3.00ppm)

This unit is the most appropriate for Koi keepers with the range it tests for.  The mid range unit goes up to 9.99ppm, suffice to say if we were testing for that we’re in big trouble!


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The unit’s range, resoltion and accuracy are as follows:

Range – 0.00 to 3.00 ppm NH3-N
Resolution – 0.01
Accuracy @ 25°C – ±0.05 ppm ±5% of reading

What does this mean in reality?  Water with 0 ammonia could actually give a reading of 0.05ppm.  Water with ammonia of 0.05 could actually give a reading of zero.  A reading of 0.25ppm on the unit could be 0.19ppm to 0.31ppm.

Ammonia - HI-700 Ammonia Low Range Colorimeter - (0.00 to 3.00ppm)

Ammonia – HI-700 Ammonia Low Range Colorimeter – (0.00 to 3.00ppm)

Inside the box you get the checker, 2 cuvet (the test tubes) and reagents for 25 tests.  The ammonia test using dropper bottles, 4 drops of each reagent.  I’m not a fan of any dropper bottles to be honest, too often you don’t get ‘clean’ drops of the reagent, sadly that for me is the downside of this test kit.  One of the tips for getting consistent accurate results is to ensure the bottle is held directly vertical, rather than at an angle.

The very first test that I did using the ammonia checker gave a 0.00 result, immediately raising my suspicions, not because I anticipated there being ammonia, just the fact it recorded zero.  A different system gave a minor level of ammonia which was more expected and reassuring that the unit was working.  The readout on the screen actually needs to be multiplied by 1.214 to give an ammonia (NH3) reading.

Hanna Ammonia LR Checker showing reading of 0.03ppm

Hanna Ammonia LR Checker showing reading of 0.03ppm

Replacement reagents for the HI700 cost £23.88 for a further 25 tests, making each test 95p.  Reagents sufficient for 100 tests cost £61.74, making each test under 62p.


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It is possible to get a standard value calibration set of cuvet from Hanna which contain liquid of a known colour in order that the unit (reagents) can be checked for accuracy.  For anyone with concerns about the accuracy/consistency of the results from the Hanna Ammonia Checker these may be a worthwhile investment. They cost £25.08 but are sealed cuvet that can be reused repeatedly just for checking the unit’s accuracy.

Nitrite – HI-707 Nitrite Low Range Handheld Colorimeter

The low range nitrite unit measures values up to 0 to 600ppb (parts per billion).  For those unfamiliar with parts per billion, it can be converted to parts per million (mg/l) by dividing by 1000, i.e. 100ppb = 0.1ppm or 0.1mg/l.

Range – 0 to 600 ppb NO2-N

Resolution – 1ppb

Accuracy @ 25°C  ±20 ppb ±5% of reading

Allowing for accuracy of the unit 100ppb could in effect be 75ppb – 125ppb or 0.075ppm – 0.125ppm.


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The number also needs to be multiplied by 3.3 to give the nitrite reading, so our 100ppb is actually 0.33ppm or mg/l, and our total range 0.25mg/l – 0.41mg/l.

Nitrite - HI-707 Nitrite Low Range Handheld Colorimeter

Nitrite – HI-707 Nitrite Low Range Handheld Colorimeter

Hanna Nitrite LR showing reading of 88ppb

Hanna Nitrite LR showing reading of 88ppb

Inside the box you get the checker, 2 cuvet and enough reagent for a rather stingy 6 tests.  The reagents for the nitrite test are provided in powder inside foil lined sachets.  A neat little addition to the packets (compared to 20 years ago) is a set of scissor lines to follow.  Cut along the lines and you can pinch open the packet to make a little ‘chute’ down which the powder will slide into the cuvet.

The results I’ve obtained from the Hanna Checker across 4 systems of different maturities have been entirely consistent with what I would have expected.  Extremely low readings from the mature systems, whilst being able to follow the new system to their peak before maturing and dropping.

A set of calibration cuvet is available for the Nitrite LR Checker, these are priced at £34.26, should the user be concerned about the accuracy of their unit.

A pack of 25 Nitrite LR reagents costs £20.16, making each test 80p.  300 sachets can be bought for £119.16, making each test under 40p.

Chlorine – HI-761 Total Chlorine Ultra Low Range Handheld Colorimeter

This unit was bought as a direct result of my frustrations with tap water purifier units and wanting to know more than the oft used DPD4 tablet test is used just to see whether a water sample has the presence of chlorine or not, without putting a value on it.


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This unit will detect the presence of any chlorine in the water, whether free chlorine or as chloramine.  It measures from 0ppb to 500ppb or 0mg/l to 0.5mg/l.  If testing untreated tap water its quite possible that your levels of chlorine would exceed what can be read by this unit.  Hanna’s standard total chlorine tester (HI-711) can read to a higher level of 2.5mg/l.  However, testing water from a purifier you would expect the reading to fall well within the range of the ‘Ultra Low Range’ unit, in fact you’d be hoping it to be zero.

The unit has the greatest degree of accuracy of all 3 here with accuracy @ 25°C ±5ppb ± 5% of reading.

 

Chlorine - HI-761 Total Chlorine Ultra Low Range Handheld Colorimeter

Chlorine – HI-761 Total Chlorine Ultra Low Range Handheld Colorimeter

As with all units, it comes complete with 2 cuvet, and reagents to carry out 6 tests.  As you can see the reagents are supplied in sachets of powder.

25 sachets of reagents for the ULR Total Chlorine Checker cost a reasonable £12.84, or 51p per test.  100 sachets can be bought for £33, or 33p per test.

Verifying the Chlorine Checker is perhaps easier than others, testing tapwater, and testing tapwater treated with liquid dechlorinator easily proved it knew when no chlorine was present in a sample or water.  Sadly it soon proved the shortcoming of several tapwater purifiers, that will be the subject of another article.  What it also proved was they effectiveness of the Evolution Aqua Detox dechlorinator unit, so much so that I have 3 of them running now.


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0ppb total chlorine reading from EA Detox unit

0ppb total chlorine reading from EA Detox unit

The Total Chlorine ULR Checker is, for some reason, the only unit that I chose to purchase the calibration checking set for, probably because I was conscious of wanting to be more sure that the results I was getting were accurate.  It was out of stock at the time I ordered the meter and arrived a couple of days ago.

 

Total Chlorine ULR Calibration Checking Set

Total Chlorine ULR Calibration Checking Set

 

The set contains the 2 sealed cuvet as pictured.  The first is clear which should give a reading of zero on the checker.  The second is tinted to the colour of a reading of 199±15ppb, i.e. a reading of between 185ppb and 215ppb.   The reading of 190 on the Hanna Checker was taken from the pink cuvet confirming that the unit is working accurately within the accuracy tolerances.  The calibration checking set can be used repeatedly and as you can see the certificate confirms it has a life of 3 years.

Conclusion

As I alluded to earlier on in the article, that fact I’m still using the Hanna Checker units, and indeed purchased another after starting to use the Ammonia and Nitrite, really speaks for itself.

I really think they are fabulous little units, and anyone frustrated with trying to match tests with colour charts, or would prefer to see a ‘real’ number should consider investing in them. Certainly it seems I’m not alone in thinking this, as I’ve seen a number of very positive comments regarding the units on Facebook whenever they get mentioned.  I have also seen some people question the consistency of results.  The only time I’ve had ‘odd’ readings is once or twice with the ammonia unit.  Inevitably I could have predicted the strange result from knowing one of the drops of reagents didn’t quite come out correctly.


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There is an interesting webinar provided by Hanna Instruments where they talk about getting the best from your Hanna Checker units, including tips for ensuring consistency of results.  It’s well worth watching it for the 12 minutes or so that it runs – https://register.gotowebinar.com/recording/7113448106240463623

Without question the reagents are more expensive than a ‘manual’ test kit, however, in the scheme of other costs associated with the hobby I don’t think that they are unreasonably expensive, and of course, you get what you pay for!

I’ve also found the service provided by Hanna Instruments first class as well, from ordering to next day delivery and to dealing with their customer service and technical departments.

 

 


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