alk and cal . you can get it from bulkreefsupply.com.
There is a lot of information on this site you can reed on or watch video's on how to do this.
There is a Reef Calculator that will give you the amounts you need but you need to test your water before you can use the calc.
I dose my 24 gal tank at work and it is doing good. my 600 gal system at home I does 16 oz every 3 days of alk