Of course you can my friend.In fact i very very very strongly suggest you do, A mixed spectrum outperforms just using one or the other. Chloroplasts that make energy by interacting with light in photosynthesis come in 2 forms, 1 deals with the blue side of the spectrum and 1 deals with the red side of the spectrum. so using only one spectrum is a huge waste imo, your not allowing the plant to create as much energy as it possibley can.