Hannah alk meter vs. LaMotte alk testkit

[slojmn]

I have used the LaMotte Alkalinity test kit for years. I love my Hannah PO4 meter so I decided to try the Hannah alkalinity meter since I am testing alk every other day and it is a bit easier to use. I tested my tank water today with both and the readings were pretty different. In your opinions, which one is going to be the more accurate reading?

LaMotte Alk test kit: 150 ppm-8.40 dKH
Hannah Alk meter: 163 ppm- 9.13 dKH (the instructions note a +/- 5 ppm error deviation)

The tank is happy. SPS and LPS are all growing so I know they are sucking the alk up. In February-March the tank was drifting down to 7.5-7.4, I was slowly increasing dosing. In March it hit a low of 7.2. I just kept slowly raising my dosing bit by bit. Two weeks ago I mixed a new solution of alk, maybe it is a bit stronger because the alk numbers have risen from 7.7 up to today's mark of 8.4 according to the LaMotte test.

Anyways, Which one should I go with? I'd like to go with the Hannah, lol, its a bit easier to use. I'm happy to leave the Alk reading where it is and over time shoot for the 8.5-9.0 range.

 

[Big E]

I use Salifert, but I also occasionally use my LaMotte to see if they coincide and they always are within a few tenths.

If the Hanna is easier, more than anything, make sure it's consistent. In other words, if it consistently reads higher than the LaMotte it's fine to use it as your main tester.

 

[GainesvilleReef]

I have tested my Hannah alk checker with Fauna Marin reference solution on a couple of occasions and both times it was within 1 ppm. I also find it to the most repeatable test kit I own. If you think it's easier than the LaMotte, then I would use it.

 

[Randy Holmes-Farley Verified Community Expert]

I couldn't really say which might be closer to reality.

 

[Cory]

1.135 grams of baking soda in 1 gallon of distilled water = 10dkh.

Take it to a pharmacist to do it.

 

[slojmn]

I use Salifert, but I also occasionally use my LaMotte to see if they coincide and they always are within a few tenths.

If the Hanna is easier, more than anything, make sure it's consistent. In other words, if it consistently reads higher than the LaMotte it's fine to use it as your main tester.

I agree with you on the consistency. Good idea and what I was considering doing.

I have tested my Hannah alk checker with Fauna Marin reference solution on a couple of occasions and both times it was within 1 ppm. I also find it to the most repeatable test kit I own. If you think it's easier than the LaMotte, then I would use it.

Good to hear, thanks.

1.135 grams of baking soda in 1 gallon of distilled water = 10dkh.

Take it to a pharmacist to do it.

I think I'll use this to test both test kits for fun. Not sure about the pharmacist part though. Do you mean take my water sample to a pharmacist and have them test it? I test every other day on most weeks, sometimes every third day. I've been bitten by the alk swings too much to not stay on top of it.

 

[Cory]

I agree with you on the consistency. Good idea and what I was considering doing.



Good to hear, thanks.



I think I'll use this to test both test kits for fun. Not sure about the pharmacist part though. Do you mean take my water sample to a pharmacist and have them test it? I test every other day on most weeks, sometimes every third day. I've been bitten by the alk swings too much to not stay on top of it.

No i meant to weigh out 1.135 grams of baking soda at a phatmacy. Unless you have a good scale, it might be hard to do, theirs are great. I did that my first time, then bought a scale.

 

[slojmn]

No i meant to weigh out 1.135 grams of baking soda at a phatmacy. Unless you have a good scale, it might be hard to do, theirs are great. I did that my first time, then bought a scale.

Ahhhh, I see. thanks for the clarification.

 

[Randy Holmes-Farley Verified Community Expert]

1.135 grams of baking soda in 1 gallon of distilled water = 10dkh.

Take it to a pharmacist to do it.

I would not use that for the Hanna. It may well need a seawater solution since it is not titrating to the endpoint.

 

[Cory]

I would not use that for the Hanna. It may well need a seawater solution since it is not titrating to the endpoint.

Thanks! Good to know. Works with lamotte?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks! Good to know. Works with lamotte?

It would work with any total alk kit where you add acid until you get to the pH or color endpoint, which LaMotte is.

 

[slojmn]

I would not use that for the Hanna. It may well need a seawater solution since it is not titrating to the endpoint.

Thanks Randy, I was wondering about this as I was driving to work the other morning and figured it wouldn't work for the Hanna Meter. I'll try it with the LaMotte though. My scale at home only goes out to tenths, darn!!! I like the pharmacist idea, I'll see if they will do it for me.