I think that with that light spectrum you are limitng growth. I would definately get something with a lower k rating. Somewhere in the 6500k to 7800k range. Personally, I would go with one light at about the 6700k and the other get the ge 9325k. Before I had that combination, I had all 6700k. I could pretty much grow anything with 4 6700k lights, but things just looked a bit "muddy". After researching, I switched out half the bulbs for the 9325k and it was literally night and day. The growth rate was still there but things just looked crisper. Btw, I was running 4x55watt over a 55 gal.