I use Tropic Marin Salt and boost up Cal & Mag with the Bulk Reef additives, alk usually tests out at 10 dkh with this salt so I leave that alone , I mix 30 gals. and change out one or sometimes two five gal. bucket per week for my water change schedule. Display tank runs at 6.5-7.5 dkh,SG 1.025, mag 1350, cal 400-425, I also run 2cups of carbon replaced every 30 days, Korallin 1502 calcium reactor and one litre zeolites in a vertex reactor. I struggle to keep my alk at 6.5 - 7.5 DKH and have tested as low as 4.5 DKH with Elos test kit.