I have a 17' by 17' glass greenhouse and my plants are still not getting enough light. A friend has given me a number of light fixtures that came form a closed down sawmill. They are made by Cooper lighting and the catalog number is FM 408. They can be found on the internet. The T Type is CWA which I have been able to determine means Constant Wattage Autotransformer. They have 400 watt bulbs in them but they are just for lighting, not growing. I also have some HORTLUX metal Halide Conversion Grow lamps and they call for a S51 ballast. My question is: Is a CWA ballast the same as a S51 ballast (so I can use the Grow bulbs in these fixtures? Thanks for your help, twogone