T5 VS MH

[dirk_brijs]

what would be the maximum depth to use T5 only and MH become almost mandatory?
What about LED I guess with the 3W and 5W LED now available the depth is unlimited right?

 

[acrylic51]

A lot of things can/do factor in the penetration of both lighting systems. T5's with good reflectors rival MH setups, and MH setups can vary as well depending on a wide combination of components as well, so the big questions are, what depth tank, and what are you planning to house?

 

[wangotango]

Anything beyond 30" deep I would start considering halides. Whether or not you're overdriving the T5 will make a difference too.
I wouldn't say that depth is unlimited with LEDs. The problem is if you are going to use a really narrow optic to focus the light more to reach the bottom you are going to need to use a lot more LEDs to evenly distribute the light.