Need help with my sump.....

[Hustler]

I have a 100 gallon sump in place in switching to saltwater and I need to know where i should be adding baffles to make this work with an inline skimmer and refugium?
Its 5 foot by 18" and 24" high with a 2 inch intake at the far end about 3 inches from the bottom, The in pipes are dual 2" from the far left with an eggcrate grid for the foamies then a whole chamber i used for bio balls, a 1 inch space at the bottom of that chamber that enters to the rest of the sump......
I know i need a few baffles but Im trying to figure out from the other pics on here how high and exactly where to put em for good flow and avoiding sand/rubble in my pump????
And advice is gold to me so thank you guys in advance