What lense and height for LEDs

[d-man]

I'm contemplating building a deep 40" tank with a width of 32" or so.
I plan on using MARS chinese LED fixtures to the tune of 2side by side to cover the witch of the tank. With 1 or 2 T5s for actinics on outside of the fixtures. What optics should I use for deeper penetration and how high up to minimize dark spots and still get enough par for low light corals to be on bottom instead of up on rocks?
Thanks
Derek

 

[Ron Reefman]

40" deep tank means 60 degree lenses if you intend to have coral near the bottom.

As for how big the footprint will be at 40" inches, I have no idea. But 2 wide will probably work.

Have fun playing in a 40" deep tank. Not my cup of tea.

 

[d-man]

Great thanks.
I love deeper tanks. They make long tongs for a reason I'll manage, lol