New Build - Light Height Issues

[Kelliwilliams817]

Hey guys! Starting a build under the stairs and dealing with floor joists being in the way of the lights. If I mount the lights flush with the floor joists, they'll be 5" above the surface of the water.

The tank is 60" wide by 30" depth by 20" height and I have three Kessil A360X lights.

At a 5" mounting height, will I still get full coverage of the entire tank? Doing LPS and softies only so nothing too crazy in terms of PAR needs. I just want to make sure the tank looks good - with no shadows etc due to the light not "spreading out" enough before it hits the tank. Attached is a picture for reference of what I'm dealing with.

 

[Fish Fan]

I mean, doesn't look like you have any more room, so this may have to work

What I can say that I am running two Kessil A360we's over a 25 gallon tank, and I thought those two lights would smoke the tank, so I started with them like 9" or 10" above the water. I ended up lowering them down to about 6" above the water, and they are working well for me at that height with some of the easy to keep SPS corals.

I think the A360x's have a wider lens than my A360we's, so I am thinking you'll be good for light spread.

Good luck!

 

[Kelliwilliams817]

So ChatGPT says that with a mounting height of 5.5" and an angle of 155 degrees for the light dispersal (per Kessil), the light will travel about 13" laterally to the left and 13" to the right, so a 26" spread.

Does that sound about right? Does anybody have the math to calculate that and double check me lol