Personally I think you'd be okay if you chose a fuzzy & put him in the 300g. Their short spiky fins don't seem to scratch others as easily. They only get up to 5", I think. While volitans can get up to 12" & their long spines tend to accidentally scratch other fish (in my case, anyway) while they're swimming around. Our volitan was 3" in october and has already more than doubled. Fastest growing fish in our tank!