Help with building a led veg light

So I'd like to build a led veg light and could use some help with a parts list and guidance on how to put it together.

I'd like to make this as cheap as possible and also something efficient for a 4foot x 4foot space. I'm thinking something to replace the 400 watt mh I run now.


Any help would be great

Wondering if I can use a power supply out of a old computer? And if so what else would I need?

Go to the "Indoor Growing" forum, then click on led lighting. Every question about LEDs has been asked and answered there. Also hit up YouTube there are lots of tutorials on building your own. Good luck!