ok so i have aquired a small hex tank that is maybe 2-3 gallons
so for planning im just gonna take some rock from my main and also some sand and plop that in there so for filtration since the sides are small i dont think a hang on would work. anyone out there with a good in tank reccomendation? for lighting im gonna do one of those coralife mini fixtures but last problem is what to put in it i have thought of a mantis or a shrimp and goby pair...

so what i need is
ideas for inhabatants
ideas for filtration