Two stacked tanks one sump?

[joekidwell]

These are two breeding tanks I got second hand. My idea was to have the return go up to the top tank, then drain into the bottom tank. I just realized it will be salt creep city with all the air bubbles from the return draining into the lower tank. The return and drain holes are on opposite sides for each tank.

How can I plumb this to where I have one return that splits to both tanks?

What I have already.
From the pic left hand side is 3/4" return with check valve, bottom tank left hand side 1" drain to sump.

Right hand side top is the 1" drain I was going to plumb to the 3/4" return on the lower tank. Right hand side return not plumbed yet.

If I can split the return and have two drains that would be ideal.

 

[The_Paradox]

Why not just return to the top tank and have the top overflow into the bottom then sump? You’ll get twice the flow that way and half the plumbing.

 

[joekidwell]

Why not just return to the top tank and have the top overflow into the bottom then sump? You’ll get twice the flow that way and half the plumbing.

As the water drains it will collect air causing salt creep/spray on the acrylic of the lower tank from the air bubbles, a return will only pump water and micro bubbles if allowed.

 

[The_Paradox]

As the water drains it will collect air causing salt creep/spray on the acrylic of the lower tank from the air bubbles, a return will only pump water and micro bubbles if allowed.

Just run a durso style drain between the tanks with the emergency overflow pipe back to sump. Under full siphon you should not be pulling any air.

 

[joekidwell]

Just run a durso style drain between the tanks with the emergency overflow pipe back to sump. Under full siphon you should not be pulling any air.

Do you think I could get by running a durso from my top tank, connecting it to the existing return through the bottom of the lower tank? Gravity would have to push the water back up 9 inches. If not I'll just drill another hole in the back of the tank.

 

[The_Paradox]

Do you think I could get by running a durso from my top tank, connecting it to the existing return through the bottom of the lower tank? Gravity would have to push the water back up 9 inches. If not I'll just drill another hole in the back of the tank.

That should work. Just make sure sump can handle the over flow from two tanks should the power go out.