No water changes? Sounds sweet to me! I have 4-5" sand bed. 350 lbs in a 6ft long 125 gallon..Caulerpa in the overflow......Wet/Dry with bioballs, prefilters, and a carbon prefilter plus a prizm skimmer. What I dont have is surface agitation. Its hard with a 125 gallon long. I guess I should look into more powerheads. I was thinking of getting a Mag Driver 7... 700 gph.