How do you measure your alk?

[reefkeeper2]

I've been having issues with my Trident matching my Hanna Checker for alkalinity. The Hanna Checker is always 1 point higher than the Trident. Right now the Trident says my alk is 7.3 but the Hanna Checker says 8.3. If I test Neptune's calibration fluid with my Hanna Checker I get 1 point higher than what is listed. I bought a new Checker, with new reagent and I get the same answer. The Trident is "new" being swapped for my old one with Neptune's maintenance program. I was having the same issue with the old Trident though, and since it was operating for 2 years I swapped it out hoping that would fix things.
I don't know which value to believe. I am uncomfortable with an alk of 7.3 preferring a value in the mid 8s. I've been searching for the fauna marin calibrator but it's out of stock everywhere. Anyone else with a Trident having this issue?

 

[FREAKINRICAN69]

Following along as I’m planning to set mine up shortly.

 

[chadfish]

From my limited experience, titration is still the best and most consistent method. Salifert makes a good one. The chemistry is simple so it should be fairly accurate.

The limitations include droplet volume, human variability, and reagent age.

 

[ifarmer]

Just pick one and go with that

 

[salthobby]

My trident does the same. I even tried calibrating my trident to my tank water. Hanna says 8.0 with a brand new reagent. After using 8.0 to calibrate the Trident it still reads 7.0 when I test Alkalinity. I even tried a new reagent in the trident still tests 1 DKH lower than Hanna. You would think after calibrating to to the Tank water they would be the same.

 

[BiGGiePauls33]

@Cpage101

 

[JPags]

I find that if I do 3 different things (trident, Hannah,and icp) I get 3 different values. I just usually maintain my alk between 8 and 8.5 because my icp tests usually come back a bit lower around 8

 

[JPags]

Remember every test has an accuracy specified so you need to take that into account

 

[Reefer508]

Hobby grade testing will always have accuracy issues. My trident never matches manual Salifert test. As long as your tank is doing well don't chase a number, just use as a tool looking for swings and trends.

 

[Joker]

I currently use Hanna and salifert. But if I can get this trident working I will be doing all 3 and taking the average of all 3.

 

[Mixed Reefer]

Just pick one and go with that

I agree, it’s stability. Not numbers. If the tank looks good stay consistent. We tend to overthink sometimes. On Alk I prefer a range between 9-9.3. The Hanna checker works great for me. I think a Alk 7 is to low and if it drops anymore your tank will be peed off. Alk @ 9DKH is in safe zone in my opinion.

 

[Greg Hiller]

I make my own reagent with bromophenol blue. IMO, it's not so much accuracy that is important, but having it above a certain threshold. IME as long as it's above the threshold, you are good.