My tank dimensions are 10" by 10" by 12" high. I use an ecoxotic pico arm with 3 strips and it isn't working out for me. The colors are too white, and it just isn't bright enough for what I want. I have been hearing alot about par 38 bulbs and good reviews about them? What is the best one for color and growth? Also I would be happy to sell my pico arm for a very good price! Just let me know if you want it. It would be perfect for refugiums! Also what do I use to put the bulb into? What are the nice holders? Thanks!