mercury vapor lights

are they good for veggying the plants

yep. but HPS lights are better for flowering. research it in the forums here. good luck

Stay far away from those, they emit a very bad spectrum and are nowhere near as efficient as HPS or MH. Agrosun has one with an altered spectrum but for the price and energy use it's no value.

former post of mine about the subject. https://www.rollitup.org/indoor-growing/6748-mercury-vapor-light-bulb.html#post59250

yeah they are old school and wast alot of unused spectrums and your better off with hps or mh