Tank is 55 gallons, 79-81 degrees (depends on time of day), 1.0255 specific gravity, 8.25 ph, about 45 pounds of live rock. I'm not really sure about the weight of the sand but I have about a 2" thick layer in my display tank and a 6" thick layer in my refugium.
I dose every day...anywhere from 1 tsp all the way up to 4 tsp of Reef Builder, anywhere from 1/2 tsp to 4 tsp of Reef Calcium (depends on test results), and I've been dosing about 14 tsp of Magnesium a day which I will continue to do until my mag gets to 1470.
When I do water changes (10% weekly) my alk drops an entire 2 units DKH, which I then have to dose to get back up. Calcium isn't affected, salinity isn't affected, temp isn't affected, not too sure about mag...might drop slightly.
This info might be useful....after I mix the Seachem Reef Salt to a specific gravity of 1.025 I get the following readings in the new water (to be used for water change)...6.3 DKH, 420 calcium, 1150 magnesium.