55g sump design need advice...

[Dave C]

The distance between the baffles is determined by how fast the flow through the sump is. The faster the flow the further apart the baffles should be. I have made mine about 1" apart. The middle one is 1" off the tank bottom.

And while nothing goes in the return section but the pump and heaters, I wouldn't skimp on it as it is the section that runs dry as water evaporates. I also use that section for water changes... turn off the pump, reroute the pump to my drain and empty the return section of the sump, fill it up, turn it back to normal and you're done.

Here's the sump I'm having built. It has the refugium on one side, the skimmer section on the other (skimmer is external) and the return in the middle.