Alkalinity WHO TO TRUST ?

[FowetsDaReefer]

I need some advice please .
I have 4 different test kits

Hannah 11.2 dkh
Salifert 11.2-11.5

API 9.5-9.8 DKH ( tested at LFS )
Redsea 9.5-9.8

Which one do I believe I put the test in the pictures am I reading them right ?

Do I need to get a 5th test ?

 

[aSaltyKlown]

Quite the conundrum.

I don't think you need another test, just retest with what you have. Regarding the Hanna, how old is the reagent? Although in my experience older reagent shows a lower result.

Is that green as dark as the Red Sea kit goes? With Salifert, I go until the color changes, then I note what the level was. Then I continue and see if the color gets darker. Note that reading and keep adding titrant one drop at a time, until I do not notice the color changing. Generally a drop or two.

I'm inclined to trust the Hanna and Salifert, but would retest.

 

[nereefpat]

I think that you'll drive yourself nuts with that many different tests. I would pick your favorite and keep your tank alk stable according to that.

I don't see the different values to be that worrisome. You have 4 tests with an average of 10.5 dKH and a standard deviation of 0.8. So 10.5 +/- 0.8. That's reasonable

 

[FowetsDaReefer]

Quite the conundrum.

I don't think you need another test, just retest with what you have. Regarding the Hanna, how old is the reagent? Although in my experience older reagent shows a lower result.

Is that green as dark as the Red Sea kit goes? With Salifert, I go until the color changes, then I note what the level was. Then I continue and see if the color gets darker. Note that reading and keep adding titrant one drop at a time, until I do not notice the color changing. Generally a drop or two.

I'm inclined to trust the Hanna and Salifert, but would retest.

Thank you yes that’s as green as it gets then it goes Into yellow over dose .
i think I should to an ICP test

 

[nereefpat]

Thank you yes that’s as green as it gets then it goes Into yellow over dose .
i think I should to an ICP test

For what parameter?

 

[arafas]

I would trust hanna and salifert. You could also get some fauna marine reference solution to give them a test. But you will drive yourself crazy. I chased this too. Just stick to salifert or hanna. Salifert never let me down. Hanna could deviate after a while the solution.

 

[spsick]

You’re going too far on the Salifert, you want the purple tinge between blue and pink. You’re likely in the 10s somewhere given your other tests. I think I recall Hanna reads a little high. Don’t sweat the differences across tests. Pick one and look for consistency day to day.

 

[Mortgaged Reefs]

Just track trends. As long as you are over 7 and pH is stable you are golden.

 

[acesfull44]

I think that you'll drive yourself nuts with that many different tests. I would pick your favorite and keep your tank alk stable according to that.

I don't see the different values to be that worrisome. You have 4 tests with an average of 10.5 dKH and a standard deviation of 0.8. So 10.5 +/- 0.8. That's reasonable

This

 

[Eric R.]

Thank you yes that’s as green as it gets then it goes Into yellow over dose .
i think I should to an ICP test

ICP doesn't test alkalinity. ICP tests for the presence of specific elements, but alkalinity isn't an element. If you send a water sample for an ICP, they will report it, but they'll just choose something similar to the test you are doing and then report those results.

You also don't need to target a specific number for alkalinity. Any number is a rather wide range is fine, as long as it's relatively stable. I'd recommend testing freshly mixed saltwater using whatever salt you use, figure out what test seems to give you the most consistent results and that you find easy to use and read, and then target that number using that test. Unfortunately the number you get might change when you get a new batch of reagents (or salt), but just test a new batch of saltwater.

 

[n2585722]

If you are worried about it get some Multi Reference solution by Fauna Marin and check your test with that. I got some to check my checker and the Hanna alkalinity tester was 6.6 which is what the reference is suppose to read. There is 100ml of solution. Most tester use 10ml so my guess is you can get 9 test per bottle. It has known values for calcium, magnesium, potassium, salinity, alkalinity, strontium, nitrate and phosphate.

 

[anthonygf]

I have been in your shoes. All good advice from what I see, that is why I stick with Salifert for most and Hanna for a few others. Those two I found are the easiest to use and get consistent results. Salifert and Hanna are my favorites.

 

[anthonygf]

If you are worried about it get some Multi Reference solution by Fauna Marin and check your test with that. I got some to check my checker and the Hanna alkalinity tester was 6.6 which is what the reference is suppose to read. There is 100ml of solution. Most tester use 10ml so my guess is you can get 9 test per bottle. It has known values for calcium, magnesium, potassium, salinity, alkalinity, strontium, nitrate and phosphate.

Great tool. I will also try it out. Thank you.

 

[Troylee]

Oh daneilson! Haha

 

[Eric R.]

If you are worried about it get some Multi Reference solution by Fauna Marin and check your test with that. I got some to check my checker and the Hanna alkalinity tester was 6.6 which is what the reference is suppose to read. There is 100ml of solution. Most tester use 10ml so my guess is you can get 9 test per bottle. It has known values for calcium, magnesium, potassium, salinity, alkalinity, strontium, nitrate and phosphate.

A known reference is a good suggestion. I should either DIY some or get a kit like that. Though is there a way to calibrate different tests if you find that the results aren't accurate?

 

[TheBear78]

How are you reading the Red Sea syringe? There has been more than one post on here about where to read when there's an air gap...

 

[n2585722]

A known reference is a good suggestion. I should either DIY some or get a kit like that. Though is there a way to calibrate different tests if you find that the results aren't accurate?

I usually use the percentage of difference to adjust the readings. But most of mine were not that far off. I had a old packet of phosphate reagent so I also used that on a second reading with my phosphate meter and it was off even more the opposite direction so also if you get a reading that is too far off in may be a good idea to try a new batch of reagent with the reference solution. Here was my results on my tester or test kits.

 

[AFHokie]

Second the color comment on salifert. Also, your syringe reads .025-.024 which corresponds to 11.7-8 however, with the couple drops too far that you went it would probably land you right around 11.2 like the Hana says.

I always did salifert wrong until I read this:

Alkalinity titration endpoint pH & Salifert endpoint color

TL;DR: The endpoint pH is 4.41, and the endpoint color is that "lavender" color I've been telling people about. Over the years, there have been many threads on R2R and other forums debating a couple of basic details relevant to testing for alkalinity in reef aquaria. One of the most...

www.reef2reef.com

My salifert and Hana Alk are always within 0.2 of each other

 

[mike550]

I use the Hanna and Salifert so that’s my bias. Keep in mind that the Hanna will drift low as the reagent gets old (lots of articles on that). For Salifert I’m opposite of @spsick and to the pink. There’s a nice video on Saltwater Aquarium about titration. That said you’re within a drop or two.

What is the Alk level supposed to be for your salt? That’s a good starting point. Or even just measure new saltwater as a simple reference

 

[jsker]

The only thing I can add, is. Since I switched to using a piperaptor and tips I have had very consistent testing with Hanna checkers. Before I was using the syringe and tip over and over and I was getting inconsistent testing. I attribute that to dried and oxidized reagents.

If you are looking for a really consistent test besides Hanna, Look into the Aquaforest tests. The test, test consistent with the Hanna. I am still testing my MG with Aquaforest test until I get comfortable with the new Mg test from Hanna