What is the preferred Calcium supplement?

[Cichlid Dad]

Yeah... actually, I just ordered that today. It seems simple enough. And to be honest, I'm a bit intimidated and overwhelmed by dosing.

The last time I tried it ( gravity drip of Kalk ), it was an absolute disaster. I ended up having to do a 50% water change on a 145 gallons. That didn't help. I got disgusted and redid the entire tank from scratch.

https://www.bulkreefsupply.com/reef-calculator
This is all you need to be able to dose what I showed you. If you have questions pm me