There is certainly more than one right way to filter an aquarium and each of those approaches has unique pros and cons.  As it pertains to saltwater aquariums, sumps are one of the best options for filtration but they are not absolutely necessary. You can successfully maintain a saltwater aquarium using a traditional aquarium with internal, hang-on style, or even canister style filters so long as you are dedicated to maintaining that filtration appropriately.

So why do saltwater hobbyists usually prefer to use a sump?

In order to best answer this question, it's best we examine this from both angles. Traditional aquariums actually have some great benefits but a sump is equally advantageous and can open up new doors as you progress through the hobby. 

Benefits of a Sump with Overflow
  • Conceals equipment below the tank
  • Runs quieter and looks more streamline
  • Increases total water volume
  • Surface skimming for more effective filtration
  • Allows for more advanced and powerful filtration equipment
Benefits of a Traditional Aquarium
  • Affordability
  • Easier and faster to set up
  • Leaves more room for storage under the tank
  • Filter maintenance is often easier but required more often

The combined advantages of a sump ultimately outweigh the affordability and easy setup that come with a traditional aquarium. You have access to a much wider array of compatible life support equipment that ultimately allows you to create a more effective filtration system. The resulting stability opens up the door to more advanced livestock and will better help you achieve long-term success. 

It really boils down to your own personal preferences and goals for the aquarium.

First-time tank owners working within a budget are often best suited to a traditional aquarium because you can learn the ropes without significant investment and still find success. As you gain experience and become more familiar with aquariums, a complicated sump begins to make much more sense and is far less intimidating. 

Read Article: What Is A Sump? - Filtration and Refugiums For Your Aquarium