Hanna Phosphate Checker Review: notable compromises still worth the resolution and portability

By Jake Adams on Apr 20, 2010

hanna phosphate checker pocket colorimeter

The Hanna phosphate checker is a green, egg-shaped hand-held colorimeter for portable testing of phosphate concentration with digital precision. If you’re like us, you’ve probably been wondering how Hanna could make such a small and affordable little colorimeter that could even begin to stack up to the accuracy of larger colorimeters from Hanna and others which cost ten to twenty times more than the $40-50 checker. Hanna was kind enough to send us a review unit of the little colorimeter for stacking up against our workhorse Hanna C 203 Multiparameter Ion Specific Meter. Over the last week we have performed dozens of tests where each reacted sample was read both by the Hanna Checker and Hanna c203. In every case the Checker was well in line with the readings of the C203 although some drawbacks of the checker became apparent when it was put to regular use. Continue reading to find out how the Hanna Checker still delivers on good value that will make it a worthy tool for precise measurement of phosphate in reef aquaria.

The Hanna checker is very easy to use. Turn it on, insert an unreacted sample of water to get a zero baseline, then add a reacted sample and take a measurement. Such simple steps are impeded by the fact that the green egg colorimeter likes to turn off every 10 seconds. We suppose this is to preserve battery life but there is no way to reopen the cuvette, carefully add the reagent and shake/invert it for 20 seconds, and reinsert the cuvette in under ten seconds. Furthermore, by holding down the only button you can set the timer to take a reading in 3 minutes, the length of time that the sample needs to be reacted for. Finally, after the three minutes are up the reading is displayed for only ten seconds after which it shuts off, and is not displayed once the unit is turned back on again. Ten seconds may seem like long enough but take a phone call, get distracted by a text message or bend over to tie your shoe and your sample has been colorimetered, displayed and erased and you’re out the 5 minutes and the roughly $0.25 it costs per reagent packet. However, since the egg-orimeter ships with two vials, we quickly developed a workaround which largely addresses the flash reading: one cuvette is filled with unreacted sample and the second cuvette is reacted and timed outside the sequence of the egg-orimeter.

Compared to the larger C203, the Hanna Checker / Egg-orimeter gave phosphate readings from the same reacted samples which we were almost always identical in the low range and only slightly off at higher concentrations. For our freshwater planted tank, tap water and RO water all readings were 0mg/l. One reef tank was 0.02mg/l and 0.03mg/l from the egg-orimeter vs the C203 and for a fish only aquarium the level was 2.20 and 2.25mg/l from the two units respectively. We made a phosphate reference solution using 0.3l of Seachem’s Flourish Phosphorus (4500 mg/l) additive for planted aquaria to 999.7 ml of RO/DI water for an expected PO4 concentration of 1.35 mg/l. Both the Hanna Checker and Hanna C 203 gave readings of 1.31mg/l when testing this solution. One final note is that the Hanna Checker was significantly faster at zeroing and taking readings than the tabletop C203; whereas the egg-orimeter usually did it’s measurements in 2-3 seconds, for the C203 it usually takes 10 seconds to read a sample.

It will be a long time before long term performance of the egg-orimeter becomes better understood but for now, we feel the $40 hanna phosphate checker will be very popular with aquarists who obsess over nutrient levels of their SPS tanks and for aquarium professionals who need a practical, portable device for delivering accurate, digitally precise phosphate testing.

hanna phosphate checker pocket colorimeter

pickle

Looks like some sort of “high tech” toy from the 70s (Speak & Spell).

“Would you like to play a game?”
pickle

Looks like some sort of “high tech” toy from the 70s (Speak & Spell).

“Would you like to play a game?”
Kayle

Is it just me? or does the box look like a pregnancy test?
Kayle

Is it just me? or does the box look like a pregnancy test?
http://reefme.com Troy

OK where can I get one of these egg shaped dealys… my favorite shop marine depot doesn’t seem to carry them yet.
http://reefme.com Troy

OK where can I get one of these egg shaped dealys… my favorite shop marine depot doesn’t seem to carry them yet.
http://coralidea.com Jake Adams

I failed to mention that TB Aquatics hooked up this review, and they were the first to list the egg-orimeter on their site. Believe they have them in stock now.
http://coralidea.com Jake Adams

I failed to mention that TB Aquatics hooked up this review, and they were the first to list the egg-orimeter on their site. Believe they have them in stock now.
http://reefbuilders.com Brian Blank

Well for the price of a couple of traditional test kits, you get a pretty good reading compared to deciphering shades of color. Wish they made a line of these for other parameters too.
http://reefbuilders.com Brian Blank

Well for the price of a couple of traditional test kits, you get a pretty good reading compared to deciphering shades of color. Wish they made a line of these for other parameters too.
http://www.advancedaquarist.com/ Shane Graber

I’m trying to understand why Joe Reefer would need one of these. Yeah it gives you readings down to 0.01 ppm phosphate, but do you *really* need to have a highly accurate reading when it comes to phosphate and reefkeeping? Bottom line there would be if you see a positive test with a Salifert, Lamotte, Hach, etc, test do a water change and/or run some phosban.
http://www.advancedaquarist.com/ Shane Graber

I’m trying to understand why Joe Reefer would need one of these. Yeah it gives you readings down to 0.01 ppm phosphate, but do you *really* need to have a highly accurate reading when it comes to phosphate and reefkeeping? Bottom line there would be if you see a positive test with a Salifert, Lamotte, Hach, etc, test do a water change and/or run some phosban.
Alex

There is a similar comparison from reef.hk
http://www.reef.hk/forum/index.php?showtopic=7770
Alex

There is a similar comparison from reef.hk
http://www.reef.hk/forum/index.php?showtopic=7770
Craig

Great product, especially that it’s cheaper than some of the reagent kits. I don’t test PO4 often, but I’d be happy to never again make guesses at shades of blue.

Jake, I think there might be a problem with your two-cuvette workaround. For maximum consistency you should use the same glass for both the zeroing and the sample. Irregularities in the glass can skew readings. I’ve even read that you should mark the top of the cuvette in order to realign it the same after adding the reagent.

That said, I’ve heard that applied to other colorimeters. I don’t know if it’s necessarily required/helpful for this one.
Craig

Great product, especially that it’s cheaper than some of the reagent kits. I don’t test PO4 often, but I’d be happy to never again make guesses at shades of blue.

Jake, I think there might be a problem with your two-cuvette workaround. For maximum consistency you should use the same glass for both the zeroing and the sample. Irregularities in the glass can skew readings. I’ve even read that you should mark the top of the cuvette in order to realign it the same after adding the reagent.

That said, I’ve heard that applied to other colorimeters. I don’t know if it’s necessarily required/helpful for this one.
iggy

Shane,

It’s nice to know when trouble shooting though. Without this your guessing even if you run it less than monthly. Definately not essential like alk cal, and mag

What is NECESSARY would be a copper tester as all test kits I’ve used are vague and way off. QT for fish are difficult enough
iggy

Shane,

It’s nice to know when trouble shooting though. Without this your guessing even if you run it less than monthly. Definately not essential like alk cal, and mag

What is NECESSARY would be a copper tester as all test kits I’ve used are vague and way off. QT for fish are difficult enough
http://www.advancedaquarist.com/ Shane Graber

IMO it’s overkill for testing phosphates — at least for a reefkeeper. For trouble-shooting, a semi-quantitative test would be adequate. Really all you need to know is a ballpark figure and the colorimetric tests would suffice in this area. The majority of the phosphate test kits test down to 0.1 ppm and the Salifert one even tests down to 0.01 ppm. Really what happens if you find out you have elevated phosphate levels which a semi-quantitative colorimetric test kit / test strip would give you is to either do a water change or run phosban/rowaphos/po4-minus/etc. Whether you know you have 0.18 ppm phosphate from the Hanna instrument or somewhere between 0.1 and 0.2 ppm phosphate from a Salifert kit you’ll end up doing the same thing.

Where this tester would shine, however, is for testing Calcium, Magnesium, Alk, Copper (QT tank) where you need higher precision. The trick would be getting a color change reaction to take place w/ a max @ 525 nm to be able to use the Hanna tester for these dissolved ions. Maybe Hanna will come out with one for Ca, Mg, and alk.
http://www.advancedaquarist.com/ Shane Graber

IMO it’s overkill for testing phosphates — at least for a reefkeeper. For trouble-shooting, a semi-quantitative test would be adequate. Really all you need to know is a ballpark figure and the colorimetric tests would suffice in this area. The majority of the phosphate test kits test down to 0.1 ppm and the Salifert one even tests down to 0.01 ppm. Really what happens if you find out you have elevated phosphate levels which a semi-quantitative colorimetric test kit / test strip would give you is to either do a water change or run phosban/rowaphos/po4-minus/etc. Whether you know you have 0.18 ppm phosphate from the Hanna instrument or somewhere between 0.1 and 0.2 ppm phosphate from a Salifert kit you’ll end up doing the same thing.

Where this tester would shine, however, is for testing Calcium, Magnesium, Alk, Copper (QT tank) where you need higher precision. The trick would be getting a color change reaction to take place w/ a max @ 525 nm to be able to use the Hanna tester for these dissolved ions. Maybe Hanna will come out with one for Ca, Mg, and alk.
Joe Reefer

I need one
Joe Reefer

I need one
http://www.blueworldaquariums.com Spencer

I disagree with part of the review. The unit will turn off automatically after about 2 minutes, not 10 seconds. Maybe you got a faulty unit? After the reading is displayed, you have about 10 seconds before it turns off. But there is no reason to be swapping cuvettes on the units I’ve tested.
http://www.blueworldaquariums.com Spencer

I disagree with part of the review. The unit will turn off automatically after about 2 minutes, not 10 seconds. Maybe you got a faulty unit? After the reading is displayed, you have about 10 seconds before it turns off. But there is no reason to be swapping cuvettes on the units I’ve tested.
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Anonymous

The timeout period on these checkers is downright silly and Hanna’s refusal to fix the issue is somewhat puzzling. The issue poses a real usability problem that detracts from the overall value of the unit. Hanna needs to start listening to end users instead of lab engineers.
Anonymous

Ok I have been reading about Hanna Checker for quite sometime
However one of the things I have not found is replacement chemicals when they run out… Can they be bought separately?
Since each test gives only so many to test-
Also how many test can I do with each kit?
Thanks

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