Fauna Marin KH issue

[Nikolai_VN]

Hi Randy and fellow reefers.
I am using Fauna Marin Balling Light method, and discovered some issues come along with KH.
At first, my tank today is 400L (105 gal)
Ca: 460
Mg: 1490
KH: 7.5
My test kit is Hanna Dkh, Salifert KH.
I use AquaCalculator to adjust my dosing. Ca, and Mg are fine. But the KH is not stable as i wanted.
App say it took 110ml from 7.5 to 8.5. Then i dose in 8pm: 100ml, at 8am i use Hanna and it read 7.7. I was dosing twice at my app say (200ml/day) but KH is still 7.x
One more thing, 3 days ago, my empty tank is 8.5 Dkh, and i put some softy in (acan, cloves, blasto, torchs, hammer) all in small size.
But after a day it go from 8.5 to 7.5 when i keep dosing 200ml/day back then. It not normal because my tank is new, coral is arrived 3 days ago, it cannot use KH that fast.

So should i keep trusting fauna manin KH? Or change my KH to another product?

 

[arking_mark]

Tank will have abiotic (precipitation) and biological consumption of Alk/Ca to form Calcium Carbonate. Additionally, as nitrate increases Alk will be consumed. When Nitrate decreases the Alk will be returned to the tank.

 

[Nikolai_VN]

So i should check my nitrate?
Currently my nitrate are at 8.

 

[arking_mark]

So i should check my nitrate?
Currently my nitrate are at 8.

Not necessarily. I was just providing you with ways a tank's Alk can get consumed.

If your tank is relatively new, Calcium Carbonate may more easily precipitate out on other Calcium Carbonate surfaces such as sand. As the tank ages those surfaces will accumulate impurities such as Phosphate which will limit or inhibit this abiotic precipitation.

So even tanks with little biological Alk/Ca demand will still consume Alk/Ca.

 

[Nikolai_VN]

Thank you for information.