I had a RB value unit (early model) on my softy cube. I had some good results with coral growth but after about a year I started getting a wicked hair algae outbreak. Did some research and found some others had a similar issue so I switched to an AI Hydra 26. Immediately I noticed a much better colors and ability to tweak the colors with the AI unit, and the hair algae disappeared. I'v been an AI fan since. Don't mean to knock the new RB units, I have heard great things about them but my experience with one of the older models was not so great.