Walk into almost any aquarium shop in Mumbai, Delhi or Chennai and you will find an arowana in a tank near the counter, sleek, prehistoric-looking, moving with the slow confidence of a fish that has no natural predators in its home rivers. The shop owner will mention luck, prosperity, feng shui. What he is less likely to mention is that the fish in that tank is a juvenile, and that a juvenile arowana grows into something your flat almost certainly cannot accommodate.
What the arowana actually is
The arowanas kept as pets belong mainly to two species: the silver arowana (Osteoglossum bicirrhosum), native to the Amazon basin, and the Asian arowana (Scleropages formosus), native to rivers across Southeast Asia. The Asian arowana, the red, gold, and crossback varieties, is the one most associated with luck in Chinese and Indian communities, and it is also listed under CITES Appendix I, meaning international trade in wild-caught specimens is banned. Legally sold Asian arowanas in India come from licensed farms and carry microchips; if a seller cannot show paperwork, the fish is almost certainly illegal. The silver arowana is far more commonly sold here and is what most buyers actually take home.
How large it gets, and how fast
A silver arowana in the wild reaches 90 centimetres to 120 centimetres in length. In a home tank with adequate space and feeding, it will reach 60 to 75 centimetres within two to three years. That is not a fish you can move to a bigger tank later, by the time most owners realise the current tank is wrong, the fish is already stressed, its spine is beginning to curve from the confinement, and its eyes may be starting to droop downward, a condition called drop-eye that is linked to the fish constantly staring at objects below the waterline in a tank too shallow for it to behave naturally.
The minimum tank size recommended by experienced arowana keepers is 500 to 700 litres for a single adult silver arowana, with a footprint long enough, ideally 180 centimetres or more, that the fish can turn without bending. This is not a community tank. Arowanas are surface predators that will eat anything they can fit in their mouths: smaller fish, frogs, large insects, and in the wild, small birds and bats taken from low branches. In a mixed tank, they are a threat to every other occupant.
What the tank and the room need to handle
A 600-litre tank filled with water weighs roughly 700 to 750 kilograms before you add substrate, equipment, and the stand. Most Indian flats, particularly in buildings more than fifteen years old, are not designed for this kind of point load on a single floor area. Before setting up a large arowana tank, the floor structure needs to be assessed, this is not overcaution, it is the reason experienced keepers place large tanks against load-bearing walls or on ground floors.
The tank must have a tight-fitting, heavy lid. Arowanas are powerful jumpers, this is how they catch prey in the wild, and an uncovered tank is a death sentence. The filtration system needs to turn over the full tank volume several times per hour; arowanas are messy eaters and sensitive to ammonia and nitrite spikes. Water temperature for silver arowanas should be maintained between 24°C and 30°C, which in most Indian cities means a heater in winter and monitoring in summer. The fish also needs a dimly lit environment with some cover at the surface; bright, bare tanks produce chronic stress.
Feeding and the cost of keeping one
Juvenile arowanas are typically fed live or frozen foods: small fish, earthworms, crickets, and prawns. Adults eat larger prey. Transitioning an arowana to pellets is possible but takes patience and consistency; many owners never fully manage it and continue feeding live fish, which carries the risk of introducing parasites. Feeding live feeder fish from unknown sources is one of the most common ways arowanas contract internal parasites and bacterial infections.
The ongoing cost of keeping an arowana, filtration media, electricity for the heater and pump, food, and periodic water testing, is meaningfully higher than for most freshwater fish. Add the upfront cost of a tank large enough to house an adult, a sump or canister filter rated for the volume, and a stand engineered to hold the weight, and the total investment for a single fish runs into tens of thousands of rupees before the fish itself is purchased.
The luck question, answered plainly
The belief that arowanas bring wealth and good fortune is rooted in their resemblance, the large scales, the red or gold colouring of some varieties, the dragon-like profile, to symbols in Chinese mythology. The fish has been associated with prosperity in Chinese communities for decades, and that association spread through Southeast Asia and into India through the same cultural networks that brought feng shui into mainstream home design. There is nothing harmful in the belief itself. The harm comes when it drives someone to buy a fish they cannot properly house, on the assumption that a small tank will do for now and a bigger one can come later. For the fish, later is often too late.
An arowana kept in a tank that matches its needs, large, well-filtered, covered, with appropriate water parameters and a diet it can thrive on, is a genuinely impressive animal to observe. It is one of the oldest surviving fish lineages on earth, largely unchanged for tens of millions of years. That history deserves a tank worth living in.