Lighting and Growth

[smacky]

I am using a coralife 48in 6700K 4X65watt compact fluorescent fixture over 8 plants. This is my first indoor grow but I have grown many outdoors and at this age they were alot taller. The plants are 8 weks old and are about 4 to 7in tall, they are the densest plants I have ever grown, but they are short, the stems are outrageously thick. Why so short? Is it my light? I am using a hydro setup with GH nutes, they are on an 20/4 light cycle, and have CO2 supplementation. I'd love to have the density of growth but the height just isn't there. I also have 10000k and 20000k actinic lights, used 4 my saltwater aquariums, they too are 4X65 watt 48 in compact fluorescents. How would they do? I do have a 400w HPS I was going to use for flowering when they get taller, would using one of the compacts with the HPS hurt anything? Any info would be greatly appreciated.

[iGotAnewHobbie]

possibly u have the lights a little too close trying back them off forcing the plant to stretch but i would like to say a small bushy plant can achieve the same yield as a tall plant if pruned properly."it's not the height that matters its the yield"

[HvyFuel]

Leave your light alone. Prune the lower branches that aren't getting light. Sounds like an excellent SOG (Sea Of Green) set up.