Hi BCReefer,
Just to clarify. Are you talking about
:
a.) Trying to plumb your system without any holes in the tank?
or...
b.) Running the drain out of the side of a drilled tank?
If the answer in b. the answer is yes you can do that.
If the answer is a. the answer is no, it will not work. You will need something called a "hang on back (HOB) overflow box." This will create the stop and start siphon effect required. If you create the siphon effect with simple PVC piping it will do one of two things (both of which will result in a flooded floor):
a.) The flow through the PVC pipe will not be as fast as the flow from the return pump (from the sump), causing water to spill over the top of the display tank.
b.) The flow through the PVC pipe will be faster than the return pump, causing the water to drop to the pipes intake level and breaking the siphon effect. When this occurs the water will no long flow through the PVC pipe and the return pump will fill the display till it spills over the top.
If you opt for an overflow box do some research and buy a model that works well. Some are very reliable while others have been known to lose their siphon effect and cause floods. I don't use one so I can't help you in that way but I am sure someone will be able to recommend one.
Hope that helps.