Types of Saltwater Aquariums

There are many different types of Saltwater Aquariums possible and the variations are endless.  However, there are a number of main types of saltwater aquariums for you to select from.  They have very similar parallels with the types of freshwater aquariums possible but the overall effect is quite unique to saltwater.  The differences are due to the inherent differences between saltwater coral and freshwater plants as well as the differences between the freshwater and saltwater fish commonly available.  A lot of fish will do better with a mature live rock system with copepods and microfauna.  What does this mean?  Well, we are about to start a new 29 gallon saltwater aquarium and plan on seeding mostly dry rock with a little live rock and letting it mature for close to a year before adding any coral or fish.  Even if you started with all live rock we recommend you let the tank and rockwork to settle, cycle, and mature for at least 3-4 months before really starting your system.  Patience and planning will pay off in any type of saltwater aquarium.

Passive Community Saltwater Aquarium

Passive Community Saltwater Aquarium

This type of saltwater aquarium is similar to it’s freshwater counterpart.  The biggest difference is there are far fewer species of schooling fish to choose from but there are a lot of species that can be kept individually or in small groups that will interact peacefully with one another in a passive community saltwater aquarium.   Some of these species are bottom dwellers, some prefer to hide in rockwork, some are mid level or upper level fish, and they typically range from small to fairly large.  With this type of tank you will want some live rock and this type of saltwater aquarium is ideal of you want to also have a saltwater coral reef aquarium.  You will want to vary the types of fish you get according to their eating habits and where they like to hang out in the tank.  For example, you don’t want to many tangs or too many small copepod eaters like mandarin gobies.  A clownfish, a hawkfish, a tang, a few schooling chromis or cardinalfish, a firefish or similar fish, a goby or two will make for an ideal passive community saltwater aquarium.

Saltwater Coral Reef Aquarium

Saltwater Coral Reef Aquarium

Like with freshwater planted aquariums, there are actually a number of variations possible with this type of saltwater aquarium.  We will go over these in more detail on the Reef Tank / Coral Aquarium page.  To summarize this type of saltwater aquarium you can have a mushroom coral and soft coral tank that requires less lighting and less demanding water quality requirements and will be compatible with a wider range of species of saltwater fish thereby accommodating a wide range of different types of saltwater aquariums.  There are also a lot of hard corals and other specialized corals that are compatible with fewer species of marine fish and require greater light and often much higher, virtually perfect, water quality.  Also, with a coral reef tank with a lot of live rock you will want a good variety of invertebrates to keep the rockwork clean and free of algae which will be important for the corals.  This means fish that will eat any invertebrates such as some larger wrasses, triggers and puffers will not make for good reef fish, even if they don’t eat the corals directly.

Semi Aggressive Community Saltwater Aquarium

Tropical fish in giant aquarium, close-up
Large Semi Aggressive Community Saltwater Aquarium

Some aquarists might like the greater interaction this type of saltwater aquarium can provide and the type of fish available in a semi aggressive community saltwater aquarium.  However, as saltwater fish are so valuable it is important to plan this type of saltwater aquarium extremely carefully to minimize aggression and fish loss.  Tangs, hawkfish, clownfish, damsels, dottybacks, foxface/rabbitfish, butterflyfish, angels, wrasses, and anthias are some of the fish that would likely get along in this type of saltwater aquarium but you wouldn’t want all of those in there at the same time.   Some of these typically do well in passive aquariums also but others will be too aggressive around passive fish.  Also, fish like angels, foxfaces, and butterflyfish will nip at many corals and you’d only want one fish in this grouping unless you had a really large tank as they are all similar types of fish.  You could try keeping them with mushroom corals and larger fast growing soft corals along with keeping them well fed to minimize any damage they might cause to the corals by nipping at them.  Without a fish in that grouping you could keep any type of coral but you still need to pay attention to lighting and water requirements.

Large Community Saltwater Aquarium

Large Community Saltwater Aquarium

Like it’s freshwater counterpart you could also have a community aquarium of quite large fish.  There are quite a lot of saltwater fish over 10 inches or so that would get along with one another, especially if they grew up with one another in the same system.   Although, it might be possible to have something like this with some limited types of corals, when you have a Large Community Saltwater Aquarium it will typically be a Fish Only With Live Rock tank often designated as a “FOWLER” tank.  A lot of Tangs will get up to a foot long including the Blue Tang made famous by the Finding Nemo movie.  Tangs are just an awesome species and get along well in any type of system.  The Yellow Tang is a better fit for tanks 55-120 gallons though.  You need a tank at least 120 gallons (180+ is even better) for a Blue Tang and most other Tangs so be aware of that.  The larger wrasses such as Lyretail Wrasses are also a good fit in this type of aquarium.  The larger Angelfish are also a good fit and possibly even some of the Lionfish, Eels, Hogfish, Porkfish, Puffers, Cowfish, and Groupers.  There are even some fish such as the Porkfish that you can establish a school of huge saltwater fish with.  How cool would that be???  Your looking at a 300 gallon or larger tank for that at the least

Large Community Saltwater Aquarium
Large Community Saltwater Aquarium

so it won’t come cheap.  As a reference with a 180 gallon tank you could have up to maybe 5-6 or so fish that could get up to an average of a foot long.  Many of the fish that I listed here like the Angelfish will feed on coral and algae to some extent in the wild and will need a very varied diet that includes both frozen and large pellet preparations that have a wide variety of protein sources in them.  Some like the Tang really should have a sheet of algae in the tank to graze on.  Some like the puffers will need the regular addition of live marine snails and/or crabs to feed on in order to stay healthy.  Cut up fresh shrimp and seafood from a good market will also help feed some of these big girls and boys when they mature.  With a tank like this denitrification with a filter such as with the Aquaripure Nitrate Removal Denitrator Filter will really cut down on the costs of water changes tremendously.

Species Specific Saltwater Aquariums

This type of saltwater aquarium is less common than species specific freshwater aquariums as saltwater fish will typically have the same water requirements.  However, there are a few exceptions.

Trigger Aquarium

This fake pic shows a trigger in a community tank ... DON'T DO IT!
This pic shows a trigger in a community tank … DON’T DO IT!

Triggers are an extremely aggressive fish and aquarists should really be cautioned about this.  It’s really hard to think of a good tank mate for them as they are so ultra aggressive.  They will need a big tank and they really do not play nice with other fish, even big ones, even another trigger.  It’s probably best to leave them alone really but maybe a Volitan Lionfish or Wolf Eel might work (?) … Just be forewarned and try to avoid the temptation to add them even to a Large Community Saltwater Aquarium.  Trust me, we tried it a long time ago and even a porcupine puffer was constantly harassed when the Trigger matured.

Shark or Ray Saltwater Aquarium

Bamboo Shark Tank

Sharks and Rays will need a large aquarium with NO ROCKS and a fine sand bottom.  Most other fish will really prefer rocks in the aquarium.  There are really only a couple of types of sharks and rays commonly available.  So you will have a bare tank with one fish in it.  Think about it … kind of like with Triggers, they are really best left alone and out of your imagination unless you’re REALLY REALLY obsessed and dedicated to this type of saltwater aquarium.

Seahorse / Pipefish Saltwater Aquarium

A Seahorse tank with Marine Plants!
A Seahorse tank with Marine Plants!

Now this is a species specific type of saltwater aquarium truly worth having!  Seahorses are normally tank raised so they are “guilt” free!  Also, they are great with live rock and almost any corals.  You can even keep a couple in a 30 gallon tank.  When mated they are close to one another and adorable.  However, they do require fairly good water quality and a relatively gentle current.  Also, they are fairly delicate and can be kept with only the most passive of fish and so it’s often recommended they be kept in species specific tank.  However, a few Chromis, a firefish, and maybe a few other types of the most gentle fish available would make for decent tank mates.  A fish such as a mandarin goby, while peaceful enough, have similar feeding habits and can outcompete the seahorses or pipefish for food.  Be aware that seahorses and pipefish normally only live for a couple of years in the wild so don’t get too terribly attached.  They also feed on copepods and you will want a mature set of live rock and microfauna before adding them.  They also often utilize Marine Plants which we have a whole page dedicated too!