yeah and the valves would be one that require electricity to open them, this means that should there be a power failure the tank doesn't just emtpy itself onto the floor and as an added bonus would make the system more energy efficient. there would also be a sensor to check the water level in the sump, so if for some reason a pump fails, the sump wont flood.
This is my (rather basic) competition entry. The tank is a relativly standard tank, however the filtration is slightly more unique. The system is designed for a reef setup or could be very easily modified for an unplanted tropic/cold freshwater tank such as an african cichlid tank. (not being a reef owner, this is based on the information is have learnt, so if there are any problem with the design please let me know and i will attempt to fix them). i have used blender3D for the design and modelling, which anyone who has tried to use before will know is a bit of a nighmare to use, especially on a very slow laptop. below is a general view of the tank and part of the cabinet (without doors):
this view shows the grid system at the bottom of the tank, the weir at the back and the outlet nozzel(bottom right of image):
this view shows equiptment inside the cabinet at the bottom:
red pipes indicate dirty water. blue/puple pipes indicate RO/pure water. green pipes are the returns to the tank. the four tall tubes on the rightof the main sump are: nitrate filter (yellow) carbon reactor (black) phospahte reactor (silver) protein skimmer (white) the main section of the sump can be filled with live rock (for marines) or bioballs (for freshwater) in the end section of the sump there are two returen pumps( with the outlets at opposite ends of the tank, this allow for wave simulation) the small tank at the end is an RO topup tank. the green box at the back of the cabinet contains a series of electronicaly controlled valves, these allow for the gravel to be autoamtically cleaned in certain areas of the tank, the pulet of this can either go into the first stage of the sump or straight out to a drain via a hose.
as a last note i am awar that the pipesare not all the right diameter, however is it means ahell of a lot of work to correct this. comment/suggestions/recommendations welcomed, thanks for looking.