I've been using bulbs like this on all my tanks for a while now. They seem to work fine for the plants that I'm growing and are pretty cheap. The only problem that I have with them is that they make a fair bit of heat from the transformer at the base of them. Also, I understand that they aren't intended to be mounted sideways like I have mine. I haven't noticed any problem using them like that, but I'm sure it shortens their life. Jesse _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member