Converting obsolete Hanna Nitrate Low Range Checker into a pH or Phosphate Checker?

[MikeTheNewbie]

Hello fellow reefers,
I recently started using the Hanna Nitrate HR and I think it is a huge improvement over the Low range checker.
With this new checker I no longer dread testing Nitrate so me and my tank buddies are very happy with the purchase
The problem is that I ended up with a $50 (now $37) paperweight. Trying to sell it would make me feel I'm trying to take advantage of someone (I don't think it is worth it even for those with Ultra Low Nutrient systems).
Looking for alternatives to repurpose it, I realized that it uses the same 525 nm LED as the pH and Phosphate checkers and remembered that the battery compartment has a connector with several exposed pins which I assume are used for calibration and possibly reprogramming.
Reverse engineering microcontrollers is a bit out of my league so I wonder if any of the smarter reefers/tinkerers out there have considered doing this or can provide some guidance reprogramming their Hanna Checkers.
Thanks!

 

[MnFish1]

Hello fellow reefers,
I recently started using the Hanna Nitrate HR and I think it is a huge improvement over the Low range checker.
With this new checker I no longer dread testing Nitrate so me and my tank buddies are very happy with the purchase
The problem is that I ended up with a $50 (now $37) paperweight. Trying to sell it would make me feel I'm trying to take advantage of someone (I don't think it is worth it even for those with Ultra Low Nutrient systems).
Looking for alternatives to repurpose it, I realized that it uses the same 525 nm LED as the pH and Phosphate checkers and remembered that the battery compartment has a connector with several exposed pins which I assume are used for calibration and possibly reprogramming.
Reverse engineering microcontrollers is a bit out of my league so I wonder if any of the smarter reefers/tinkerers out there have considered doing this or can provide some guidance reprogramming their Hanna Checkers.
Thanks!

I thought about this. Then realized that the cost of doing so would far outstrip any benefit. I would sell it on Ebay. Let the buyer decide whether its worth it or not. By the time you have researched it, tested it, etc - you've probably spend hours of work. One suggestion - call Hanna - they have a great tech support team - and ask them if there is a simple way to do it?

 

[MikeTheNewbie]

Makes total sense MnFish1. I can't tell how many times I have worked on DIY projects that end up costing more than buying the off the shelf product (like all my woodworking ones) but I enjoy DIY a lot, specially when things work out and I learn to do something new.
I'll take your advice and reach out to Hanna but my experience has been that companies are not thrilled with people tinkering with their products (i.e. ecotech). Understandably, tinkering can lead to broken devices and people might want to claim warranty even when they caused the problem. Let's see how it goes with Hanna. I think it would be nice from them to support the Nitrate LR owners with that option.

 

[MnFish1]

Makes total sense MnFish1. I can't tell how many times I have worked on DIY projects that end up costing more than buying the off the shelf product (like all my woodworking ones) but I enjoy DIY a lot, specially when things work out and I learn to do something new.
I'll take your advice and reach out to Hanna but my experience has been that companies are not thrilled with people tinkering with their products (i.e. ecotech). Understandably, tinkering can lead to broken devices and people might want to claim warranty even when they caused the problem. Let's see how it goes with Hanna. I think it would be nice from them to support the Nitrate LR owners with that option.

Yes - I wasn't trying to discourage you - If it was a 3000$ piece of equipment I might give you a different answer. My 'guess' is that there is a way to swap out the chip (or something) in the unit with a pH one (i.e if you bought a used pH one - or could get one for free). My guess is that some people will still want to use the Hanna LR checker - which is why I said maybe just sell it.

 

[Dan_P]

Hello fellow reefers,
I recently started using the Hanna Nitrate HR and I think it is a huge improvement over the Low range checker.
With this new checker I no longer dread testing Nitrate so me and my tank buddies are very happy with the purchase
The problem is that I ended up with a $50 (now $37) paperweight. Trying to sell it would make me feel I'm trying to take advantage of someone (I don't think it is worth it even for those with Ultra Low Nutrient systems).
Looking for alternatives to repurpose it, I realized that it uses the same 525 nm LED as the pH and Phosphate checkers and remembered that the battery compartment has a connector with several exposed pins which I assume are used for calibration and possibly reprogramming.
Reverse engineering microcontrollers is a bit out of my league so I wonder if any of the smarter reefers/tinkerers out there have considered doing this or can provide some guidance reprogramming their Hanna Checkers.
Thanks!

You probably can’t reprogram it easily but you can generate a calibration curve to convert the Checker’s numbers to a concentration of a new analyte. The low range NO3 Checker is programmed to measure very colored solutions. This means, for example, as a phosphate Checker it would read 0 at too high of a PO4 level. It would be OK for a Chlorine or Alkalinity Checker, maybe pH.

 

[MnFish1]

You probably can’t reprogram it easily but you can generate a calibration curve to convert the Checker’s numbers to a concentration of a new analyte. The low range NO3 Checker is programmed to measure very colored solutions. This means, for example, as a phosphate Checker it would read 0 at too high of a PO4 level. It would be OK for a Chlorine or Alkalinity Checker, maybe pH.

This is an intriguing idea. How would you do this, i.e., what would be the gold standard you would use. I.e. lets assume you're trying to make a PO4 meter - would you have to mix up varying known amounts of PO4, or use another checker to determine various PO4 levels - and then create the curve. Either way - I would think that error in preparing the curve would make the 'new' checker have a much lower accuracy/precision wouldn't it?

 

[Dan_P]

This is an intriguing idea. How would you do this, i.e., what would be the gold standard you would use. I.e. lets assume you're trying to make a PO4 meter - would you have to mix up varying known amounts of PO4, or use another checker to determine various PO4 levels - and then create the curve. Either way - I would think that error in preparing the curve would make the 'new' checker have a much lower accuracy/precision wouldn't it?

You have captured the essentials of the idea. Make different comcentrations and correlate the concentration to the Checker reading. Most of the error or variation will arise from the preparation of the mixtures, Do a sloppy job and the correlation will have small R^2? Do a careful job and the error will be close to the Hanna Checker error.

 

[MnFish1]

You have captured the essentials of the idea. Make different comcentrations and correlate the concentration to the Checker reading. Most of the error or variation will arise from the preparation of the mixtures, Do a sloppy job and the correlation will have small R^2? Do a careful job and the error will be close to the Hanna Checker error.

the problem unless you have lab grade testing/weighing/etc chemicals - you cannot do this accurately enough to make a calibration curve - IMHO

 

[Dan_P]

the problem unless you have lab grade testing/weighing/etc chemicals - you cannot do this accurately enough to make a calibration curve - IMHO

I think that I would turn your idea around a bit. I would propose that unless you are doing work that requires high accuracy and precision, generating a sufficiently accurate calibration curve for the saltwater aquarium hobby is within reach of most reefers, i would add that a large portion of reefers probably would not enjoy the process

 

[MnFish1]

I think that I would turn your idea around a bit. I would propose that unless you are doing work that requires high accuracy and precision, generating a sufficiently accurate calibration curve for the saltwater aquarium hobby is within reach of most reefers, i would add that a large portion of reefers probably would not enjoy the process

Yes - this was my point (kind of) LOL