API Alkalinity

[elbowdeep88]

I got an API ALK test to use in conjunction with my Hanna checker. Hoping to arrive at a reference color that I can use as I make some adjustments rather than keep using the Hanna twice a day.

 

Thought others might find this helpful as I was never sure how ‘yellow’ the endpoint was supposed to be.

 

Tank reading at 8.0 on the Hanna (checked it twice in succession and got 7.9 and 8.0). Pictures of tests using 7, 8, and 9 drops of API ALK shows that you are going for a greenish yellow, not as yellow as the drops from the bottle.

 

[Origami]

Over the years, I've found that the API alk kit has some variation from lot to lot and maybe even had variation in where the line was on the vials. This variation always bothered me, but the kit is attractive in both its price and its simplicity.

 

So, to reduce the cost per alk test, I used to "calibrate" the cheaper API kit to a reference solution (see another post I recently made about an alk reference solution) by adding the drops to vial and then adding the solution (using a syringe) to the vial until I got the point where the color began to change. From there, I noted the amount of solution used on the test kit box and, from then on, used a syringe to measure out my tank water into the vial. It was a strategy that worked pretty well when I wanted to test alk frequently for whatever reason.

 

You can also calibrate the API against the Hanna in this manner.