7.3 dKH Alkalinity?

Just received my Salifert Alk test kit today and measure my levels. My dKH is 7.3. Is this a good reading? I read that it should be around 8-10 with corals. I currenlty only have two Xenia's and an Acan. Im trying to solve my faded Coralline algae problem and slow growth. Could this be an issue? My led fixture is from rapid led, I run it at fairly low power so I wouldn't burn anything, becuase it has the capability. Lighting has also been constant, no sudden light shocks.

Current Parameters

pH: 7.3
Salinity: 1.026
Temp: 78.5-79.5
Calc: 425
Alk: 7.3
Phos: 0

My mag test kit will arrive in a few days so that will be updated.