Alkalinity testing ?

[Mrx7899]

I check my alkalinity daily with a Hanna checker today my alkalinity went from 7.7 yesterday to 7.1 today so I tested two more times and got 7.1 then I tested again with a different reagent and got 7.2. So I decided to check it with my Red Sea kit and I got 9.0 two times so I'm like which one do I believe is it 7.1 or 9. They are usually pretty close to each other which one would you believe. I know 9 is not bad but I like it around 8. I run a kalkwasser stirrer but about 2 weeks ago it wasn't keeping up with my alkalinity and I started doseing alkalinity at night with a dosing pump

 

[hybridazn]

I would go with the Hanna checker, you did it a few times with very similar results. The red sea kit offers too many chances for error with testing or something could have went bad with the kit itself.

 

[Mrx7899]

That's what I figured the Red Sea kit is pushing about a year old so I'll test it tomorrow if it's still a little low I'll pump up my dosing pump a little bit tank is really eating up some alkalinity lately. I ordered a salifert kit just to have another option

 

[reefwiser]

.1 change is not something I get excited about. This can be caused by just a little bit extra reagent picked up. Your Alk will drift up and down a little during the coarse of the day.