Help raising calcium

[2reefs]

Having issue with cakcium and all and need help. It is a 21 g cube rimless I added coral and Acro including water change twice 3 gallons each time my coral are absorbing calcium. Alk has been stable at 6 but calcium went down from 360 to 260 in 3 days oh is stable at 8.2. I have liquid seachem reef advantage and reef calcium I am thinking of adding the calcium part wait for 2 days and retest. Let me know your opinion.

 

[Boomer]

It is a testing error 2reefs. It chemically can not happy.

 

[2reefs]

Will test again

 

[Wilson416]

Test again and if needed dose 1 ml at a time test day after to see levels