Is my sump in backwards?

[chuckfu5]

Before I plumb this up is my sump in backwards?

Drain is on the left return on the right.

If I flip it around the skimmer will be in the back. Also do I have it drain the in skimmer chamber or the small chamber in front of it.

Also where do you guys place your sensors for the auto top of?

How do I tell where the water level will be so I know how far down to run the drain pipe?

First sump I have worked with.

 

[DeniseAndy]

Hard to tell from the picture, but the way I like to run a sump is simple.

Drain from tank into a chamber that is required to go through refugium or protein skimmer, then the return is the last place the water should flow into and back to the tank. The auto top off is done in the return chamber.

It really does not matter how much you have in the sump after that as long as direction of water goes from drain to return.