sump input please

[achilles101]

Im designing new sump for custom tank set up setting up new 210g tank trying to deside what sump arangement to use as far as algae scrubbers, deep sand bed, metalla. just looking for input of what people are using and liking.am not confind to size as it will be behind main tank but looking at useing 90 gallon sump with double herbie.
thanks for any input