KH very low

[Radion Dream]

There was a problem with my tank for which I couldn't figure out why.
The tank is 65 days old today. I cycle to day 33. And then to start releasing corals.
Current parameters:
NO2: 0.05
NO3: 5
Po4: 0
KH: 5
Salinity: 35ppt
Salt used: Tropic marine Bio sync
Food: feed every 3 days. reefbosster + ab plus
Microbiology: AF Np pro and AF pro bios daily use
Soft coral reef tank as shown. No fish or shellfish
Input measurement salt KH = 8
However, when I received the Redsead test, the KH was only 5. Measured 6 times in 3 consecutive days, KH was still 5.
I am very concerned about the KH loss ???
Somebody help me ???

 

[P-Dub]

What is your calcium? High calcium levels, above 500 or so, have a tendency to lower alkalinity as I understand it. I'm sure @Randy Holmes-Farley will correct me if I'm wrong.

 

[Randy Holmes-Farley Verified Community Expert]

Cycling an aquarium generally lowers alkalinity. I'd likely just boost it with something like baking soda.