I have been using the 1000 watt Agrosun MH growing light in a Hydrofarm Reflector to expose my POP prints with. The light is set up in my classroom and does double duty growing tomatoes and lettuce in a hydroponics garden. I will be leaving my classroom in a month to assume a more administrative role. This means more money but less space. I will not be able to set my gardens up, at least not where I will be working, so no light set up means no printing. With my very young kids at home and the rising cost of utilities setting the light up there is not practicle. Sooooooo.... I thought I would build a UV exposure box for home. Now my questions. 1-DOes using the light source dramatically increase your electric bill? 2-How are the sprial bulbs working? or should I stick to the straight bulbs? 3-How much is invested in the construction costs? I am handy so building it will not be the problem cost outlay might be. I assume it is much cheaper to build it myself than buy a premade unit. Hopefully this is not too personal. 4-Anyone build a unit just using the BL ready made fixtures from Home Depot and just screwed them into the box and plugged them into a power strip with a main power switch on the strip?