A sump gives you added water volume, a place to keep your equipment hidden (heaters, skimmer, etc) you can add macro algae, more sand, more LR
for filtration plus if you have critters/livestock that cause you problems you have a place to put them until you can deal w/ them.
The canister would mainly be a choice over a HOB
. Looks better, provides more flow. You also can put LR
in the compartments for filtration.
One thing to keep in mind is that SW
filtration is different. You won't have any of the sponges in your filters (or shouldn't). Your clean up crew will take care of all that stuff. So in the can you would put LR
rubble, any filter media you want to run (carbon, purigen, GFO
That's kinda the 5,000 ft view