Alkalinity

[Aquattro]

Originally Posted by coolhandgoose

Are you sure the measurement is in dkh or in meq/l (I think that's what the other one is called)

good point. I think that value is fine for dKh...too many units for alk

[coolhandgoose]

Other way around, that's really low for dkh.
If its meq/l I think it's fine.

[Seriak]

It was 62 then 66 ppm.

[Delphinus]

Yeah that's really low. What salt are you using?

[Seriak]

I initially used a half bucket of 8 year old IO and the rest has been new reef crystals.

[Delphinus]

Weird.

Are you dosing yet? I'd start by dosing Alk for now to bring that up to targets .. The Hanna's measure in mg/L CaCO3 which convert to dKH or meq/L as follows ..

The instrument directly displays the concentration of alkalinity in ppm of CaCO3. Alkalinity conversion:
1 ppm CaCO3/L = 0.02 meq/L
1 ppm CaCO3/L = 0.056 dkH

There's also this: http://glassbox-design.com/2009/alkalinity-conversion/

.. So I think you want to target your Hanna readings to be in the 150-160ish ballpark. I think..