Order a box Reef Rock
or other base rock. It will become LR
(coated with bacteria) during your cycle. 15 pounds of LR
just is not enough to handle the bio load of a stocked tank. It would be fine for 1 fish, but you're going to have to add more rock sooner or later. Might as well add a bunch of base now and let the tank cycle with that and the bit of LR
Don't plan on a PWC
untill you have added much more rock and gone through a proper cycle.
What other equipment do you have?
Do you have a sump or a wet/dry filter?
Please list everything.