How many AI 16 HD Primes recommended

[Reaper_Six_Four]

I have a 48x20(d)x21(h) 72 gallon tank. I'll mostly be focusing on LPS and softies but may also entertain some SPS at a higher placement in the tank. How many 16 HD does everyone recommend for a tank dimension like this?

 

[ilyad]

AI says the Prime can cover 24 inch square, so if you go by their recommendation, two would be sufficient. I find that to be lacking though. I would say for LPS and softies, you can probably do fine with 3. Later if you decide to go the SPS route, you can always add a 4th.

 

[X-37B]

4-16hds or 2-32hds.
This is my 36x24x12 frag system running 3 16hds.

 

[Hooz]

I hate shadowing, so I always opt for more lights. On a 48" tank I would run 4x Primes. I'd group the two outside (end) lights on one "tank" and then group the two inside lights on a separate "tank" so you can adjust the two groups to different intensities (running the same schedule) for super even PAR from end-to-end.

That would also give you the headroom to grow whatever you wanted in that tank.

 

[CasperOe]

Check this video from BRS

 

[rsumner]

I agree with @CasperOe -- the BRS video goes into a ton of detail on the Prime 16 especially since you're running a standard 4ft tank. The great thing about the Prime is it's easy and cheap to add another later if you need it once you start to get growth that introduces shadowing.