I thought it would be interesting to find out from other members how often, how much and how you do water changes. Maybe we can all learn a better way of doing it by sharing methods. /site/DesktopModules/NTForums/themes/_default/emoticons/smile.gif My gross water volume is approx. 140 gallons but net is around 115 gallons with the amount of live rock I have in there. I change out approx. 40 gallons every 3 weeks using Oceanic salt that is heated and mixed with a MJ1200 for 24 hours prior to use. My tank is in a spare room with no plumbing or drains in it so I have to use 2) 44 gallon Brute Rubbermaid containers to bring in and take water out. This normally takes me about 45 minutes total.