i agree with firewater, i had 5 biocubes setup at once and small water changes weekly is good, skimmer is a personal choice, but shouldnt be needed if you do water changes frequently, do rock rubble instead of bioballs, also if you want to do a mini fuge in the rear chamber might want to start it now before you completly setup , just look thru the nano section alot of diff setups on biocubes