[nabee24]

I have been doing a lot of reading. One of my books are saying that I should change my lights every 6mo, even if they are working, becuase it emits red wavelengths? I am using 2 blue and 2 actinic lights made by Giesemann.

[Ninong]

I'm not sure what you mean by "two blue and two actinic lights?" Are you talking about fluorescent lamps? If so, are you talking about T12, T8 or T5, and normal output, VHO or HO? Or, are you talking about compact fluorescents?

How often you change the lamps depends on exactly what you have. Some VHO lamps need to be changed out every 6-9 months but that can vary depending on the type of ballast used. Some compact fluorescents should be changed every 12 months but others may be good for 18 months or more. T5 HO lamps should probably be changed about every 12 months but it's possible to run some of them longer, depending on the type of ballast used.

Exactly what do you have? If they are fluorescent lamps, what is the wattage, what is the manufacturer's claimed Kelvin rating, are you running an electronic ballast?