sump tank
 

Just bought a 420 gallon tank 84x42x28 I would like to use my 150 5x2x2 tank as a sump can you get away with not having a bunch of balffles in there can i just put a wack of live rock and strong pumps to push it all about in there and have a prity good flow back up to the tank just have a shelf for the skimmer to sit on as it is a nice 150 and may still want to use it again soon

yes u can - many people use giant rubbermaid tubs with no baffles