if you get the model with the
PC lighting, they're nearly the exact same unit. if you want high light corals & nems then you'll have to decide between the 28G
LED nanocube & the 29G HQI bio cube. If you're going reef you're going to be replacing the pump & the back chambers in either one. so it's a personal preference. I will tell you that there are more mods for the biocubes over the nanocubes.