Fluorescent T5 lights are ideal. They produce plenty of light and do not produce much heat. Perfect for those growers with mothers in a tent or cabinet. Fluorescent T5 Grow Lights - Grow Lights
MH for sure if its one or the other but they make [ame="http://www.amazon.com/Hortilux-Eye-Super-Blue-1000W/dp/B0027Z2G4Y/ref=sr_1_2?ie=UTF8&qid=1322741960&sr=8-2"]these[/ame] superblue lights that its a dual spectrum light with a 400w mh and a 600w hps inside 1 tube the same size as a normal hps light and uses the same hps ballast you dont need a mh ballast, its a 1000w bulb so you need a 1000w hps ballast to run it but that will work best I have used one of these from start to finish and had great results, I dont like or grow autoflower plants but I bet this would work great for them also
^ ive heard good and bad things about those, they run really hot apparently, but makes sense with the dual arc and all, i have HEARD they tend to fail faster due to the thermal stress, the hps that hortilux claims has 12000 hrs and their super blue metal halides only 5000, sounds like its a 5000 hour bulb. sounds like the efficiency and practicality needs some work ON a + note, the dual spectrum is apparently really welcomed by growes and loved by plants, u sometimes use dual spectrum (in seperate bulbs) and i know my plants love that, so if all else is under control im sure a 2 in 1 would be awesome.
MH provides great light, but the amount of watts can be over kill and end up costing money. Mother plants grow very well under T5's and the cost of running a 4 bulb T5 vs a 400w MH is noticeable... Good luck with whatever you decide to go with!
I have a friend who got one to use in veg and he never liked it because it was to hot compared to the t5's that he uses so he only used it a little bit, he then decided to try it out in flower with 2 other hps's - it worked fine there was no difference at all other then a cool looking 2 color light its something to see really it looks cool as hell he had 3 lights and 1 was this superblue dual light and the other 2 were normal hps - it was 2 lights in line that were hps and 1 that was between them but not inline and off to the side because the room was to small to put 3 in a row, it was sorta like a triangle - well the one that was not part of the 2 inline was the superblue but really all 3 lights overlapped that is how the setup is and there was no noticeable difference at all he has given it to another friend who was just starting out growing and he used it from early gev all the way through flower and got the same amount as the rest of us do under 1 1000w - we all helped him to make sure the plant was grown big enough before changing the light over to 12/12 and making sure he didnt mess anything up or cut it down early and it was just fine