I just noticed you're new here. Welcome to R2R!!
AI Primes are great lights. What size tank do you have? How many inches above the surface do you have the light mounted? Here's a really helpful thread to help you choose the light schedule for your Prime:
So I'm treating my nuvo fusion 10 to a AI Prime HD unit. Upgrade from the current usa pro I had. If I want to set the lights to run a 12 hour cycle that will start at 12 noon and go til around 11:30 p.m. (so I can enjoy the tank when I'm actually at home) what lighting schedule is best? Is...
www.reef2reef.com
For future reference, I would take everything your LFS says with a grain of salt and always ALWAYS research everything for yourself here first. Your LFS may be knowledgeable but keep in mind they are also sales people and there is a solution or gadget that can be sold for every issue your tank is having, but you want to make informed decisions with the most knowledge possible to succeed long term in this hobby.
I also noticed in another thread you stated your tank is 3 months old. I would not add any SPS or livestock at all for that matter until you are regularly testing your key water parameters (at least once a week) and things have stabilized. When your liverock has purple coralline algae growing on it, I think that is a good time to start adding SPS. Any sooner when your tank has not yet stabilized, and more likely than not, those corals will be dead in no time. Your thread stating you have fish dying indicates your tank is far from mature and there may be much more concerning underlying issues, so I advise you get the basics in check first.
You should watch the BRS (Bulk Reef Supply) 52 Weeks of Reefing series on youtube, it's super informative and will get you up to speed with the fundamental concepts of every aspect of reef-keeping in no time, and its entertaining. Also, the sticky threads on here are immensely helpful and I suggest reading those as well.
We are all here to help so want to make sure you get started on the right foot so you last in this hobby longer than the average person does, which data shows is 1 year.