50/50 vs straight 6700K

Go 6700. Actinics are designed to provide SW corals with a similar bandwidth of light that you would see 40-60 feet underwater in the ocean.
 
Again, I concur that 6700 (anywhere between 5000K and 8000K) is better for plants and will give you better results in the long run. I have thoroughly enjoyed the look and effects of mixing (50/50) half 5300 (or 5500 bulbs) with 6700 bulbs in the back. This to me gives the IDEAL effect of excellent plant growth for a variety of plants and also giving a terrific "NATURAL" look to the plants and fish. Some enjoy a "blueish" look to their freshwater tanks, but I do not, but prefer a natural plant coloration.
 
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