Large Fish for Big Aquariums: Arowana, Stingrays, Discus and What They Need

Big fish make a big display, and they make big demands. Before choosing a species, work out whether the tank, filtration and cooling can support the adult, not the juvenile in the shop. Here are the fish people most often ask about, with what each really needs.

Arowana

The “dragon fish” is a long, powerful, surface-oriented swimmer, prized for its presence. It needs a long, wide tank, a tightly fitted cover because it jumps, and clean, well-oxygenated water. One arowana in a spacious tank is more impressive than several crowded together.

Freshwater stingray

Stingrays live on the bottom, so floor area matters far more than height. They need a smooth sand bed, strong filtration and very clean water, and they are fish for experienced keepers. A long, low, wide tank suits them best.

Discus

Discus are calm, colourful shoaling fish. They do best in groups, in warm, very clean, stable water, which makes a well-filtered tank with good temperature control the key. They are not especially large, but they reward a larger volume.

Large marine species

Large tangs, triggerfish and groupers make bold displays, but each needs generous volume, robust life support and reliable cooling. For help choosing between water types, read saltwater vs freshwater aquariums.

Design around the adult fish

An undersized tank stunts growth, stresses the fish and shortens its life. Specify the tank for the adult size and the number of fish you plan to keep, then size filtration, cooling and structure from there. This is how we approach a custom aquarium, and it is why the weight of a large tank needs checking, see aquarium floor load.

Compatibility

Not all large fish live together. Temperament, diet and water needs must match, and some species simply eat smaller tank mates. We help plan a stocking list so the species you choose can share the tank. For smaller tanks, see the best aquarium fish for Dubai homes.

FAQ

How big a tank does an arowana need?

A long and wide one, sized for the adult. We specify it for your fish rather than quoting a single number.

Do large fish need a chiller?

In the UAE, usually yes, especially for marine species, where stable temperature is critical.

Have a species in mind? Tell us and we will design the tank around it.

Further reading: Arowana (Wikipedia) | Discus fish (Wikipedia)