Big difference from salt to fresh. Your going to remove everything in that sump and start with a clean sump. Here’s what 2 of my wet/drys look like.
FF646167-19F1-44AE-AA76-4BEE16913387.jpg this one is on a 90g. Water enters on the right into a drip plate than flows through a ball pit and into a sump with a few bags of matrix than back into tank. This next one is on a 180
C2AD991E-4703-4D80-B28D-E381B4DD09FA.jpg it has 2 chambers and a sump. Both chambers have a filter media pad in them. The sump has bags of matrix and bio-home. That’s it. That’s all you’ll need.