Hanna Working on Calcium, Alkalinity, Magnesium and Nitrate Checkers

[Paul_N]

Well, I'd consider the po4 "checker" a crappy product. I have the colorimeter and testing has shown it's not much better. As stated above, reefers target po4 levels at .03. The margin of error is .04. So if the Alk "checker" comes out and is only off by 8 dkh, would you consider that good or crappy? Here's a quote from a respected individual:
"When I evaluated the original model using a standard (Hanna by the way) and washing the cuvets and caps with high purity acid solution I got a 3 fold difference against the standard when trying to measure below 1 ppm and two fold difference between different measurements of the same concentration. This second part told me that user variation can potentially be even higher than their specified accuracy."

I can tell you from experience that original one works very well and all reports so far say the smaller "checker" works just as well. I'm just a little mad that I paid $75 for the original meter used when I could have got the checker for $40. I test twice just to be certain and I can tell you that it is never off by more than .01. If my phosphates are .01 or .05 it really is fine with me so the .04 margin is acceptable IMO. I would test with the kits and they always said I had zero phosphates. When I used the meter the first time it read .19.

Also to assume since the margin of error on the phosphate check is .04 that the alk checker will be off by 8 is a leap. You can use the tubes and powders and I'll keep using the meters...:bigsmile:

 

[ksc]

I guess it works well if you don't check it against a known standard. It get good "reports" from naive users because it spits out an easy to read number.....

 

[Paul_N]

OK the suspense is killing me. What is the known standard "in the reefing community" ? Oh wise one enlighten us naive users... You proceed to bash a product and the rest of us that use it but provide no stats or alternative.

 

[wfournier]

Well, I'd consider the po4 "checker" a crappy product. I have the colorimeter and testing has shown it's not much better. As stated above, reefers target po4 levels at .03. The margin of error is .04. So if the Alk "checker" comes out and is only off by 8 dkh, would you consider that good or crappy?

I have heard people trash the Po4 checker because of the .04 margin of error, however if you look the expensive ~$200 models have the same margin of error.

 

[Demonic]

Everything has to have a margin of error, even the test kits you and I are using. Nothing is this world is perfectly precise everytime. Why the bashing? There are people that like the product and are going to buy it, including me. Are you assuming the Alk "checker" is +/- 8 dkh, because we both know what ASSuming means. Sounds like you are sour on their products, too bad, I am sure they are hurt.

 

[stunreefer]

Well, I'd consider the po4 "checker" a crappy product. I have the colorimeter and testing has shown it's not much better. As stated above, reefers target po4 levels at .03. The margin of error is .04. So if the Alk "checker" comes out and is only off by 8 dkh, would you consider that good or crappy? Here's a quote from a respected individual:
"When I evaluated the original model using a standard (Hanna by the way) and washing the cuvets and caps with high purity acid solution I got a 3 fold difference against the standard when trying to measure below 1 ppm and two fold difference between different measurements of the same concentration. This second part told me that user variation can potentially be even higher than their specified accuracy."

The original, non "checker" version of the Hanna PO4 meter had the same exact variance as the "checker".

Who is the respected individual? And what is that quote even referring to? There's no content to determine what is being referenced as "standard" or anything else mentioned...

I'm not trying to be argumentative, I'm wanting to see where this perspective is comeing from (and letting others do the same) if it's true or not.

Liquid test kits are not nearly as "accurate" as some think in most cases, especially PO4.

 

[ksc]

Well, for most a 100% margin of error is "crappy". If my po4 is .04, according to Hanna, the meter will read anywhere from 0-.08, 100% too high or 100% too low. That quote was alledgedly from an engineer who designs similiar meters. He tested with a standard of 1ppm po4 provided by Hanna. There are some liquid kits that are better (Hach, Merk) but they cost quite a bit. I did a quick search and only found a 1 ppm standard solution for sale. Find one that is .1 or lower and I'll buy it and test my Hanna meter.
. Hanna HI 713 Phosphate colorimeter - Page 12 - Reef Central Online Community

 

[ksc]

Further reseach reveals the quote is from the creator of the reef chemistry calculator locted in the reef chemistry forum here. Here's another quote I found from JD, "From this thread, jdieck (our reef chemisty calculator man) states:

"I tried to develop a compensation graph for my Hanna and just wasted $600.00 in reference samples, cleaning solution and calibrated precisin measuring pipetes and cylinders.

Same reference sample on equipment cleaned with UHP nitric acid test 5 different times, 5 different measurements.
I got somehow consistent results in the range of 0.1 to 1 ppm, below 0.1 it was all over the place.
Basically I use it as a reference only, in other words I replace my GFO as soon as it detects anything, even 0.01."

 

[Paul_N]

My point is though there is an acceptable range for phosphates. I am happy if mine is .0 to .07. So as long as the meter reads around .03 I'm good. I don't need to spend tons of money on the test kits. There is no such thing as zero phosphates in a reef tank IMO.

 

[Tenacious716]

KSC... while I respect your thoughts/opinions, I am curious to know if you have any hands-on personal experience with this piece of equipment? Just my opinion, but I think you are getting very technical with the readings of the Hanna meter(s). I have used them and I know they work... VERY well. You must realize that (approximatly) 75% of the hobbyists who are buying this unit aren't very concerned with the .04 margin, they just want to keep their PO4 under control and get a somewhat reliable reading versus the liquid test kits that don't offer anything but a headache and skewed results.

Personally, I'm VERY excited to get my hands on these new Ca/Alk/Mag/Nitrate testers. Hanna has never disappointed me and IMO their equipment plays a crutial part in the success of my tank. It's nice to know that they (unlike most other broad companies) are focusing on making tank husbandry just a little bit easier.

 

[luke33]

These are exactly what i've been waiting for. xmas for the lazy reefer!

 

[WT INC]

it will be a huge market for them