Pat, I'd love to to have a 6 foot tank but space is an issue and at L48" x W 30"X H 24 that's 150 gallons + 30 to 40 gallons for the sump and all the plumbing, an almost 200 gallon system will be enough for a new comer to start with at least for me! Someday I hope to have a 300 to 500 gallon tank but those dimensions are what dreams are made of but dreaming is fun!!