Alk calibration fluid (?)

[ZoWhat]

My Salifert Alk driptest kit and my Hanna Alk Tester are 3-4 dKH off from each other. Not sure which one is closest to the true number.

Is there an Alk fluid i can buy to test? Where?

For example: a bottle of fluid tested to exactly 8.0 dKH

 

[DSC reef]

My Salifert Alk driptest kit and my Hanna Alk Tester are 3-4 dKH off from each other. Not sure which one is closest to the true number.

Is there an Alk fluid i can buy to test? Where?

Does most tap water out of the faucet usyally have a certain Alk? That i can test with?

Each company offer verification fluids and they actually come with the test kits....

 

[PDR]

https://www.bulkreefsupply.com/hi772-11-alkalinity-dkh-calibration-check-set.html