Do you prefer to have a water pump inside or outside a tank?

[Madmak]

My big closed loop pump is external but all the rest of my small pumps are internal. IMO if the added heat is a negative thing for your tank, go external. If it is not and you have the space in your sump, go internal.

[lastlight]

anything that can leak I try to have in the tank or plumbed above the tank. Even my rodi unit is installed above my laundry tub so if it leaks its contained. I still flood my house all the time but this helps some!