The 3 Setups for Saltwater Aquarium Inhabitants

In a general sense, there are three main setups for saltwater fish tanks when it comes to the inhabitants: Fish Only (FO), Fish Only with Live Rock (FOWLR), and Fish and Corals. 

Here's a bit about each, separated by experience level.

Beginner: Fish Only (FO)

Fish-only aquariums include only fish and sometimes some invertebrates. When you choose a fish-only aquarium, expect less lighting and maintenance than one of the other options.

Intermediate: Fish Only with Live Rock (FOWLR)

A Fish Only with Live Rock (FOWLR) aquarium is a step up in terms of complexity. The biggest addition is live rock, which is typically old coral that contains beneficial bacteria that helps to filter the water. This helps to display a more "natural" aquarium, since it mirrors what is actually in the ocean. Usually when you introduce live rock to your aquarium you can also add live sand as well. 

A step up to a FOWLR aquarium means a higher grade of lighting. You'll also need to maintain the chemical parameters required to sustain the bacteria within the live rock. That means avoiding certain chemical treatments, and the use of different filters.

Starting a FOWLR aquarium takes longer than a FO aquarium because the aquarium will have to cycle before you can add fish to it. This typically takes some weeks and requires chemical testing before adding fish to the tank.

Expert: Fish and Corals (Reef Aquarium)

In a reef aquarium, live rock, corals, invertebrates, and fish all live together as they do in the world's shallow seas. It's high risk, high reward, but if you've got the experience, it's definitely worth it for the stunning view.

As you know from the many stories on the health of the world's reefs, the parameters for a successful reef are EXACT. They require all of the right kind of equipment and attention to maintain.

The major parameters that need to be monitored include but are not limited to: salt levels, temperature, water flow, chemicals (alkalinity, nitrite, nitrate, phosphate, calcium, magnesium, iodine, and strontium), and compatibility of your tank's inhabitants.