My first grow used a 2'x4' 4 bulb flourescent that put out a combined 7,600 lumen. 2700k frequency. I looked at your light and I'd call them similar. Here's what I learned. You want your light right up close and personal to your plants or you'll get spindly growth. Considering the area you have to work with I'd consider a vertical sea of green (hang your light verticle from chain and a few hooks in the top will let you move it around) or some other low profile training that will allow you to move your light or plants to within inches of each other. I found mine were often touching the bulbs with no problems to the plants. Adjusting will be required with growth. As your light is 3000k, which is for flowering and fruiting, I'd also consider some added 6500k cfl or single bulb sticks for early/vegitative growth. I'm not sure you'd be able to mount them where they can do the most good unless you put them between your plants, then they should reflect back from the fixture in front of them as well as getting the side light. But you did say you have other bulbs so maybe just changing to the right freq (k) bulbs will do but the more light the better and spectrum does matter. AND the inside of your cabinet is white or covered in mylar right? I used shiny white wrapping paper in my smaller station and it works great. Especially in a small space , bouncing the light around really helps.