Kh testing in reef aquarium

[lindajj]

Just wondering if anyone can explain why two kh test kits by API test so differently. Both kits are in date and look identical. One tested using 9 drops and the other took 12 drops. Both bottles were tested twice, alternating, after such different results. Same result, 9 drops from 1 bottle and 12 from the other. I will now have my water tested at Lfs asap

 

[A Young Reefer]

welcome to R2R!
API test kits are known to be significantly inaccurate and faulty. I would recommend switching to something like salifert.

 

[ReefEco]

Haven't ever used API, but would agree that your different results would point to bad quality control on their part. When you add together a new test kit, or a bunch of tests at the local fish store (which I imagine cost money?) - you might consider getting the Hanna DkH checker. My most used tester, and has always been reliable for me. It is so easy, it actually makes me test Alk more often, which is not a bad thing...

 

[Rmckoy]

I’d suggest picking up a salifert or Hanna

 

[lindajj]

Took a sample to lfs and tested alk, one bottle was 11 drops and he tested with a result of 11.6 so pretty close. I have disposed the other bottle which was changing after 8 drops. Will continue using for now but replace with something better when this is all used. Thanks for you comments