i have a single 150 watt hqi sunpod with 14000K bulb. It is about 3 inches from the water surface and another 3 inches to the rock. If my rock is roughly the shape i have drawn in the picture and the acro frags are about 2 inches in height...and everyhing is roughly proportionate with my illistration, how far apart should i place the acros frags?
thank you

I would do 3-4 inches for growth.

ok so my rock is like 5 inchs in diameter at the top. as you can see it is a round shape so im trying to calculate growth for the corals growing at different angled directions and not just growing next to each other on a relatively flat surface. i hope you can understand. is the 3-4 inches suggestion accounting for this?
thank you

They'll eventually grow into each other, but I've seen a lot of tanks where this happens and it actually looks pretty neat. You can frag them when they get to close to prevent it, but unless you've got some seriously strong stinging SPS then you shouldn't have too much of an issue as long as you start them off at about 4"+ apart.

Also, it really depends on the species, like staghorns and bottlebrushes tend to do very well next to each other, whereas tabletops will steamroll over a lot of things.

And they'll grow up. Have you thought about a monti cap on one side?

I think an efflo or table acro would look good on the light because it tables outward, like a monti cap.

Monti cap on the right would look nice, because monti caps just look nice.

I say a pink birdsnest up top, with maybe a green slimer. Great looking corals, easy to keep.

Like others said, the SPS will eventually over grow each other given that they survive and you're system will be running for that long. Depending on the species, growth rate and habits will be different for each. In my experience, with good lighting, SPS often grows toward flow rather than light.

what about encrusting montis? will they grow on top of acro bases and kill them?

Montiporas are usually peaceful to each other, but some acroporas can sting montiporas.

ok i decided to just get a red planet angled at one side and a garf bonsai or another tabling acropora angled at the other side to be safe. if i plant the coral sideway, the bottom side of the coral will always be in the shade because i have a metal halide. Is this ok for acros?

The dark side will turn different colors depending on the acro. Some will turn brown but the dark side of my bonsai is a dark purple and the shaded parts of a red planet colony I've been drooling over at my LFS are greenish.

Why would you stack your rock pyramid style, go with the "V" style for single halide tanks, I chose to go with both and as far as stonies stinging each other that should be a great reason to frag. I would suggest starting with stag pieces and working up to Bonsai style. But really I would redo the stack to make the most out of the lighting.

What do you mean by V style? like wider as it goes up? All my rock consists of just 4 pieces and i struggled for hours to figure out the best aquascape... of course i did this before i changed the stock rsm hood to a sunpod. Changing the aquascape isnt an option for me at this point.

How does the bonsai grow?
Would i be able to place the red planet tabling acro on the top left corner ponting at a 45 degree angle towards the upper left and another green with blue polyped tabling acro on the top right corner pointing at a 45 degree angle towards the upper right corner and the garf bonsai right at the top pointing straight up in between the two tabling acros?

Just from my experience- for the pieces that aren't going to be placed directly vertical, buy pieces that have been growing having light exposed to them from the sides, as they will be when glued to your LR. Otherwise some acros can get pretty p/o when the direction of light changes, because it also changes their gowth habit. I have some that browned up a little from this very thing.