Types Of Saltwater Aquariums In Order Of Difficulty

When people think of marine aquariums they often envision a huge tank full of big rocks and corals, which seems very difficult to maintain and expensive to set up. However, there is much more variety to saltwater aquariums than that, and you shouldn’t discard the idea of a marine tank just because you don’t see yourself taking care of a tropical reef. Keep reading to learn more about the different types of saltwater aquariums, sorted by how difficult they are to set up and maintain.

Fish Only Aquarium

A fish only saltwater tank is probably the most accessible saltwater aquarium for beginners, as you will only need to worry about the fish. Most fish-only marine aquariums are sparsely decorated, with just coral sand, plastic decorations and the stars of the show: the fish. This is the type of marine aquarium best suited for a novice, as it allows you to get familiar with water parameters testing, managing and maintaining a marine aquarium and many hardy marine fish suitable for fish-only tanks.

As you can expect, you will still need most of the equipment for marine aquariums and the general rules of the game won’t change so much. However, you won’t need to worry about coral, which can be finicky. Some good fish species for a fish only marine tank are damselfish, yellow tanks and many other captive-bred species that don’t require a reef to thrive. Since you don’t need coral or live rock, this kind of marine aquarium is the cheapest.

FOWLR Aquarium (Fish Only With Live Rock)

This kind of marine aquarium is a mix of a fish only aquarium and a reef aquarium. The main difference with a fish-only setup is the introduction of live rock. But what is live rock exactly?

Live rock are fragments of old coral reef that are naturally colonised by marine invertebrates, sponges and all sorts of nitrifying bacteria, hence the qualifier of “live”. In a marine aquarium, live rock acts as a natural filter, and helps keeping the water parameters stable. Live rock is a must-have on a reef aquarium in order to keep your corals alive. However, it is also incredibly helpful to keep a marine fish-only aquarium in tip-top condition.

A live rock with fish aquarium is an easier to manage alternative to a regular reef marine tank, but still allows you to display beautiful and delicate marine fish to their best. You will need to let the live rock “cure” in your aquarium for about 2 to 4 weeks, in a similar process to cycling a freshwater aquarium, before you can start adding fish.

Since you won’t need to worry about live corals and invertebrates, your choice of fish in a FOWLR tank is pretty wide. For example, large angelfish and pufferfish can do well, and the angelfish will help control algae. You can even keep fish such as sharks and rays on a fish-only with live rock tank, but some species will need more maintenance than others.

Fish and Invertebrate Saltwater Aquarium

You can also keep invertebrates such as crabs, star fish, shrimp or sea cucumbers on an aquarium, but they tend to be more delicate than fish and prefer setups with live rock or even a fully fledged coral reef aquarium. However, keeping invertebrate in a FOWLR aquarium is more practical, as you won’t run the risk of your crabs or sea urchins digging at the corals and unsettling them from the substrate.

It is very important to consider the compatibility between species if you are creating a fish and invertebrate saltwater tank. Many fish natural prey are shrimps and crabs, for example, and the last thing you want is for your aquarium citizens to eat each other! On the bright side, some invertebrates, albeit delicate, are brilliant to keep the aquarium free from detritus and algae, and will work non-stop as sweepers and cleaners.

In general, invertebrates are considerably more delicate than most marine aquarium fish and you should make sure water parameters are kept very stable. Be also very careful with any medicine or water treatment you use, as some metals can prove deadly very quickly.

Coral Reef Aquarium

A coral reef aquarium is one of the most complex marine tanks to set up, but at the same time it can be absolutely stunning. Coral reefs are populated with fish, invertebrates and corals, and use live rock both as a substrate for the corals and a hiding place for fish. Fish such as clownfish (those cute orange ones with white stripes from Finding Nemo) thrive in reef aquariums.

You can keep two types of corals on a reef marine tank: hard corals and soft corals. Soft corals are easier to maintain and grow quicker than hard corals, and some are even photosynthetic so the maintenance is easier. Corals in general require very specific water conditions, and a strong current that will circulate nutrients and move away debris. In order to keep the ecological balance of a marine reef tank you will most likely need a refuge as well.

Marine reef tanks are not for the casual hobbyist as they can take a large amount of time and money to populate and maintain. However, they are not necessarily difficult provided you get the right equipment and are familiar with water testing. You will also need pretty specific light conditions that mimic the natural environment of corals: shallow reefs in tropical areas that receive large amounts of sunlight and heat.

Specialty Saltwater Aquarium

If you are after a challenge, a specialty saltwater aquarium will keep you busy. This kind of marine tanks are designed to hold a single specie of fish or invertebrate which requires very specific conditions. For example, you could have sea horses in an aquarium, or octopus or even sharks.

Each specialty aquarium is different as the environment needs to be carefully tailored to its inhabitants. For this reason, they can prove a challenge even for experienced aquarists.

As you can see, not all marine aquariums are the same and you can get beautiful results no matter your experience or skill level, provided you choose the right type of saltwater tank setup. You can also build up, and modify a fish only aquarium to hold live rock and even coral reefs as budget and time constrains allow. Learn as much as you can before you head for the fish store and you will be able to enjoy a healthy and stunning marine aquarium with much less trouble than you thought.