DSparks,
Awesome thread! I’m thinking about a build for a 25 long. You’ve inspired me to research an external box. I like the idea of more real esate, and more water volume.
My thought was to use bulkheads drilled through the back of the tank attached to loc-lines for the sump return and a closed loop (2 for the sump pump, 2 for the CL). Then I’ll have 4 “aim-able†returns going into the back of the tank. The sump returns would be high up and the closed would be in the middle somewhere. I see you have your loc-line riding up a bit above the water line. Are you having any problems with air bubbles? I saw that the loc lines are not necessarily air or water tight. So my thought was to make sure I put the return lines from the sump high up but still below the water line. I figure if I get a power loss only the water above those loc-lines will drain into the sump.
Any real world feed back you can provide would be great.
Thanks!