I bought my tank used from a pet shop across the street from me for $50.00... It is I believe a 56.1 gallon with built in overflow... I am going to post a pic of the back of it when I bought it... Can someone tell me if this is considered to be a wet/dry trickle or a back of tank sump... I am not completely clueless, but I don't know exactely what you call this... Also any opinions on how to utilize this or do you recommend build a sump in my stand... Right now I simply have large folded pieces of polyester filter floss in the top compartment... Thanks in advance!