Eden,
I wish it worked the way you have posted. I like the idea and commend your independent thinking, but you haven't created a grow light that produces all the light frequencies of a true grow light. That's not to say that this light won't help as it will, it's just you'll need to supplement it. In other words if this set up is the only light provided you won't get optimal results. I use a similar set up in one of my bathrooms as I have plants in there. It has helped but the plants are can't miss varieties (pothos, peace lilly) that grow anywhere I put them. I've also used this on a bunch of arabica coffee trees (my little Costa Rica coffee finca) and they did ok but did start to get a bit "leggy" after 6 months.
Daylight is 5500K - plants will do well under this.
MH (1000w) is 3700K - this is perfect for growing figs.
An inexpensive but "professional type" grow bulb (again MH at 1000w) will produce 110,000 Lumens and be good for an area about 5 feet x 5 feet and last - they claim - 10,000+ hours. Most folks I know replace their bulbs 1x per year as they do degrade over time.
All the above figures are approximate as I was too lazy to look them up.