Attatch my Frag Tank to Dt?

[dplantz]

I have an old 20 gallon tank that I use to use for a tetra tank that I shut down about 5 year ago when I started marine (yay). I plan on buying a Finnex 30g M tank and I have been all over the place looking for a good idea for a frag tank. After popular vote (and a limited flow of cash since I'm not old enough for a job, YET!) I have decide that I'm going to just put the 20g tank inside my tank stand and pump water from my DT to it and back.
My question for you is what type of pump would you recommend to create good flow from the hang on sump of my DT to the 20g frag tank?

 

[dplantz]

 

[shiby1510]

gravity

... although you will need a pump for the return... the size of the pump depends on if you want to use to for flow in your dt or if you are just going to use it to get it up there.
you could set it up like a sump..
for example:
left side: intake from dt
middle: grow corals
right: return

 

[dplantz]

well I want to set it up like you said, with a gravity feed to it, but what brand would you suggest for it to return the water with good flow so I could use it in place of one of my powerheads? Anyone?