I've got a large cfl but just can't get close enough to give them enough light. How much are metal halide bulbs and will the bulb go into the same shade as my hps?Should use MH instead of HPS to reduce internode length.. about 1.5 to 2 feet away. Maybe even a little bit more.
Except, get a cool tube. Don't use that bat wing. I had the same one at the beginning and have still run it for over 2 years without problems400w digital is what you need does both Mh/HPS http://www.amazon.com/Apollo-Horticulture-GLK400GW19-Digital-Dimmable/dp/B004YXDHX6/ref=pd_sbs_lg_1/184-6239264-5135065?ie=UTF8&refRID=0QB4MX1MAC3WD23C8GJB
Yes and no. Again, early stage veg plants are small. A single 400w can adequately light 4-5 up until the point where most people switch to flower (4-5 weeks from seed)depsn how many plants you grow under that 600w doesn't it?