Your tank being new it’s gonna absorb a ton po4 before the rock and substrate find an equilibrium with the water column.I started dosing phosphates to prevent the tank from sitting at 0. Kinda necessary since it’s going to be fallow for 2 months and there’s just a handful of snails and hermits in there.
I also picked up some All For Reef and will dose lightly, observing how the corals respond.