I have a pair of SI percs that are 1.5" (female) and .75" (male) in my 14g BioCube. It will only be 18 months or so before they're fully grown, and when they are fully grown they'll be about 3"-3.5" (female) and 1"-1.5" (male). I'm going to set up a tank in 3 months (probably the 29g BioCube HQI) and I'm trying to plan out the stock list. Will the SI percs in the 14g eventually outgrow the tank? If so, I would put them in the new tank that I'm getting by themselves (or with a goby friend) and I would find some other fishies to put in the 14g.