Help with Project: Piping and Pressure

What do you want to do anyway? Where is this water going to? Is it being used to raise water about the top level of the tank or is it going into a drain below the outlet pipe invert level? If it's the latter then pressure is not a problem; any pump capable of delivering 600 gpm through a 12" pipe is sufficient, but if it's the former, then you need to tell us how high the water needs to be raised and if there is any required outlet pressure, otherwise we cannot help you calculate your required pump size.

Oh, and you also need to tell us your pipe material and number of fittings e.g. valves, elbows etc so that we can calculate the frictional head losses for you.

I AM RUNNING AIR THROUGH THE TANK TOP SIDE STARTING WITH A INLET 8" PIPE BOTTOM SIDE 12" OUTLET NEED TO KNOW HOW MUCH PRESSURE I NEED TO PUSH OUT 600 CU FT LIGHT MOISTURE IS FLOWIG IN FROM TIME TO TIME BUT NOT MUCH

Can you post a sketch here? I know what you want but I still have absolutely no idea what you're trying to do, let alone be able to calculate the pump size for you because you have not answered any of my questions such as are you pumping the water to a point high above the tank or simply into a discharge point below the pipe, number of fittings, pipe material etc.

Oh, and please turn off the caps lock. Most people here will not entertain someone who posts in all capital letters because it's very rude: it's the online equivalent to shouting at someone.

To say nothing of the irritating (and almost unreadable) ALL-CAPS of the OP.