How Much UV In Watts Is Needed To Mimic The Sun For Say A 4x4 Grow Tent?

Ive Been looking at Led lights for a 4x4 grow tent, are these lastest grow lights that have additional UV, are they a gimmic, meaning are they putting UV on them without measureing the UV rays (in watts),

Ive also been looking at getting an led light, an just adding supplementing UV, but how many watts to mimic the sun. or whats the least (an adequate) amount needed in watts

If you want to add UV and as full spectrum as possible I would personally combine CMH and LED's. You get the best of both worlds IMO.

Here is a starting point to understand your question. Enjoy the read.

UV lamps &