Overflow & Return Placement for 3 Tank 1 Sump Setup

[SaltwaterScoop]

I have some questions regarding the plumbing and placement of the overflows/returns on the side tanks below.
The side tanks are 40 gallon breeders and the center tank is a Waterbox Reef 180.5.

1. Is it ok to place my overflows and returns like this for the side tanks?
2. Will there be enough room in the sump for all 3 tanks to drain (might have to run the water lower than usual).
3. Will there be enough pressure from the return pump to reach the tanks (pump is running at 30% right now). This is why I am only doing 1 return hole per tank.

What do y'all think?

 

[KrisReef]

The math is complicated but the solution is easier to find.

The lynchpin of sump area is easy to calculate when the pump is running. When the pump stops the overflow depth and return siphon depth come into play. Sump size needs to have enough area (cubic inches) to except the water depth above the lowest water level in each tank.

If the main tank is running now, how much space (cubic inches) is leftover in the sump when the power shuts off and everything drains completely? If you are 1/2 inch from the top then you have less than 1/4 inches of water depth in the 2 40’s to work with and you will need a new sump or you will need to change the way your sump is working currently.

If you have 4 inches across the sump when it drains then you can probably make it work out now.

 

[SaltwaterScoop]

The math is complicated but the solution is easier to find.

The lynchpin of sump area is easy to calculate when the pump is running. When the pump stops the overflow depth and return siphon depth come into play. Sump size needs to have enough area (cubic inches) to except the water depth above the lowest water level in each tank.

If the main tank is running now, how much space (cubic inches) is leftover in the sump when the power shuts off and everything drains completely? If you are 1/2 inch from the top then you have less than 1/4 inches of water depth in the 2 40’s to work with and you will need a new sump or you will need to change the way your sump is working currently.

If you have 4 inches across the sump when it drains then you can probably make it work out now.

After letting everything drain and settle, it looks like I have ~4.375" of room...so maybe I'm safe?

 

[KrisReef]

After letting everything drain and settle, it looks like I have ~4.375" of room...so maybe I'm safe?

My estimate is a swag, I presume you will limit the amount of return to the two smaller tanks and that they will not be draining down more than 2” when the power shuts off.