I agree with most that was stated above. Stay away from the 1 watt led. They are not very good in general. A unit with 3 watt led, and no lens is what you should go for. I don't use prefab led so I can not recommend a light. I would recommend just building one if it is possible. I use 4 vero 10. 2 @ 3000k, and 2 @ 3500k. Ran at 350ma. ~26.7v * .35a=9.345w *4= 37.38w total, in a micro cab that is 11" x 13". I am able to get it within 4" of established plants, and it makes frosty nugs. Plus it only cost me ~$50 including shipping the items. I'm rounding that up, it actually cost just under $1 per watt.
Also the silica is a great idea regardless of lights being used. It will help the plant build stronger cell walls, and improve the general health. Silica is a essential micro nutrient most people over look. This is the one I use and add it to every feeding. A small amount goes a long way.
http://buildasoil.com/products/agsil16h-potassium-silicate. If you decide to get some silica, look specifically for "agsil 16h potassium silicate " Here is a general google search for that.
https://www.google.com/webhp?source...TF-8#q=agsil+16h+potassium+silicate+in+plants
Best of luck bud. :smoking: