all the chambers are for different things, some for live rock, one for skimmer, one for chetto, one for new fish to acclimate or a healing chamber the rest just more water for the return. what i plan on doing when doing water changes this will allow me to remove 40 gallon of water and drip or slowly pump 40 gallons back . this will be all sps maybe a few chalice and zoas. mainly be sps.