Aaron: Good idea and I've been working out a way to do this myself in order to cut back on repetitive maintenance like servicing multiple filters, CO2 devices, and doing many individual water changes, etc. In fact, with plenty of plants and a relatively low fish/bio load I wonder if one couldn't just plumb the system to constantly add and remove a certain amount of water via an overflow so that little (if any) mechanical filtration devises were needed. The question is: how much water to exchange? The equivalent of a 50% water change every two weeks perhaps? Also, how to hook the tanks together: a circulating range system where the water flows from tank to tank in a circle or a central sump system where all tanks overflow into a common sump where the water is added, removed, injected with CO2 and perhaps filtered somewhat? The devil is in the details. Bob Olesen --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/