API says I’m at 9 DKH.
Salifert says I’m at 11.5 DKH.
They’ve consistently tested with this margin for a week now. So uh, what’s my actual DKH?
Got a third test kit? 
I personally don’t trust API test kits, but for alk it is usually fairly close. Are you coming to the meeting tonight? I can bring my Red Sea kit and you can test your water with it. I’ve found it to be accurate and consistent with other tests.
[quote=“TheEngineer, post:2, topic:9031”]
Got a third test kit?
I personally don’t trust API test kits, but for alk it is usually fairly close. Are you coming to the meeting tonight? I can bring my Red Sea kit and you can test your water with it. I’ve found it to be accurate and consistent with other tests.[/quote]
Working 1pm-9:30pm today otherwise I’d take you up on the offer
You could test against some freshly mixed saltwater. The alk level is something you can look up online. You can see which one is closer to the pin
I ordered the Red Sea pro alk test kit. we’ll see what it has to say
That’s what I use. Good luck!
Salifert: 10.7 DKH
Red Sea: 10.4 DKH
API: 10.0 DKH
I did a 25% water change yesterday to reset some of these values. All three kits are reading within 0.7 of each other so I feel a little better with the results.
That looks more like it.