Arowana — Accessories & Essentials

Filtration is the single most important accessory category for any Arowana setup. The bioload produced by a large carnivorous fish demands robust mechanical, biological, and chemical filtration working in concert. For tanks in the 250- to 400-gallon range, a sump-based system is generally the best investment. Sumps offer high media capacity, easy access for maintenance, and the ability to house ancillary equipment like heaters and reactors out of the main display.

Canister filters serve well as supplemental filtration or as the primary system for keepers who cannot accommodate a sump. Look for models rated for at least twice your tank volume, with multiple media baskets that allow you to layer mechanical filtration pads, biological media, and chemical media like activated carbon in a logical flow sequence. Ease of priming and self-starting capability are practical features that save time during routine maintenance.

Filter media selection determines how effectively your system processes waste. Mechanical media — sponges, filter floss, and micron pads — captures particulate matter. Biological media — ceramic rings, sintered glass, and bio-balls — provides surface area for nitrifying bacteria. Chemical media — activated carbon, zeolite, and specialty resins — addresses dissolved organics, odors, and specific contaminants. A well-designed media stack addresses all three filtration stages in sequence.

Maintenance schedules for filtration equipment should be regular but not overly aggressive. Rinsing mechanical media in old tank water every two weeks prevents clogging without destroying beneficial bacteria. Biological media should be replaced in partial batches — never all at once — to preserve the bacterial colonies that drive your nitrogen cycle. Chemical media follows manufacturer guidelines, typically requiring replacement every four to six weeks depending on bioload.

Arowanas are tropical fish that require water temperatures between 76 and 84 degrees Fahrenheit, and maintaining that range consistently is essential. Submersible heaters are the standard choice for Arowana tanks, and for tanks over 200 gallons, you will typically need two heaters placed at opposite ends of the tank to ensure even heat distribution. Running two units also provides redundancy — if one fails, the other prevents a catastrophic temperature crash.

Heater wattage should be calculated at roughly 3 to 5 watts per gallon of tank volume. For a 300-gallon Arowana tank, that means a total heating capacity of 900 to 1,500 watts, split between two units. Titanium heaters are the preferred material for large predatory fish setups because they are virtually indestructible. Glass heaters, while less expensive, can shatter if struck by a startled Arowana, creating both an electrical hazard and a risk of injury to the fish.

Heater guards or protective cages are a non-negotiable accessory for Arowana tanks. Even titanium heaters can cause burns if the fish rests against them for extended periods. A properly fitted guard allows water to circulate around the heating element while preventing direct contact. Some keepers route heaters through their sump system instead, which eliminates the need for in-tank guards entirely.

A separate thermometer — independent of the heater's built-in thermostat — is essential for verifying actual water temperature. Digital thermometers with probes provide the most accurate readings and can be positioned at multiple points in the tank to check for temperature gradients. Heater thermostats can drift over time, and without an independent check you may not notice a gradual temperature shift until the fish shows signs of stress.

Lighting for an Arowana tank balances visibility, aesthetics, and the fish's biological needs. LED systems dominate the market and for good reason — they produce minimal heat, last for years, consume far less electricity than fluorescent alternatives, and many models offer programmable features that allow precise control over intensity, color spectrum, and photoperiod.

For general viewing, a fixture producing 6,500 to 7,500 Kelvin delivers a natural daylight appearance that renders the Arowana's colors accurately without the artificial tint that very warm or very cool lights create. Adjustable spectrum fixtures let you fine-tune the look to your preference and can be shifted toward warmer tones during dawn and dusk simulation for a more naturalistic effect.

Dimmable fixtures with programmable timers are worth the additional cost. A gradual ramp-up in the morning and a slow fade in the evening prevents the startle response that Arowanas often exhibit when lights switch on or off abruptly. Some keepers program a brief moonlight phase using low-intensity blue LEDs, which allows nighttime viewing without disturbing the fish's rest cycle.

Mounting and splash protection matter in an Arowana setup. These fish are powerful jumpers, and feeding time often sends water splashing upward. Choose fixtures with an adequate IP rating for moisture resistance, or mount lights high enough above the waterline that splash contact is unlikely. Pendant-style mounts or hanging kits offer flexibility in positioning and make it easier to access the tank for maintenance without removing the light fixture entirely.

Reliable water testing is the foundation of proactive Arowana care. At minimum, you need the ability to test for ammonia, nitrite, nitrate, and pH on a weekly basis. Liquid reagent test kits are more accurate than test strips and cost less per test over time, making them the preferred choice for most serious fishkeepers. A master test kit that covers all four parameters in one package is the most economical starting point.

Beyond the core four parameters, testing for general hardness, carbonate hardness, and dissolved oxygen provides a more complete picture of your water chemistry. These tests are less urgent on a weekly basis but should be performed monthly or whenever you notice behavioral changes in the fish. Sudden shifts in hardness or KH can destabilize pH, creating a cascade of problems that are easier to prevent than to correct.

Water change equipment scaled to the size of an Arowana tank saves enormous amounts of time and effort. A Python-style water changer that connects directly to a faucet allows you to drain and refill hundreds of gallons without carrying buckets. For very large setups, some keepers install permanent plumbing with valves and drains that reduce a 30-percent water change from an hour-long ordeal to a 15-minute routine.

Water conditioners that neutralize chlorine, chloramine, and heavy metals are essential every time you add tap water to the tank. Choose a concentrated formula — one that treats a high volume per dose — to keep costs manageable on large tanks. Some conditioners also include slime coat protectants or stress reducers, which can be beneficial during water changes when the fish may experience minor stress from temperature or chemistry fluctuations.

Feeding tongs are arguably the most important feeding accessory for an Arowana keeper. These long-handled tools allow you to offer food precisely at the water's surface without submerging your hands, which protects both you and the fish. Stainless steel tongs in the 10- to 14-inch range are durable, easy to sanitize, and provide enough reach for even deep or wide tanks.

Feeding rings — floating frames that contain food within a defined surface area — help prevent pellets and other dry foods from drifting into filter intakes or behind decorations where they decompose unseen. A simple suction-cup-mounted feeding ring positioned in the Arowana's preferred patrol zone trains the fish to feed in a consistent location, which makes it easier to monitor intake and remove uneaten food.

Live food containers and gut-loading setups are practical accessories if you regularly offer live insects or crustaceans. A small, ventilated container for housing crickets or mealworms allows you to gut-load them with nutritious greens before feeding. Dedicated nets and containers for thawing frozen food keep preparation clean and prevent cross-contamination between food types.

A kitchen scale accurate to one gram is a surprisingly useful tool for Arowana keepers who want to manage portion sizes precisely. Weighing food before each feeding removes the guesswork from portion control and makes it easy to track consumption over time. If your Arowana's appetite drops or spikes, having a quantified feeding log helps you and your veterinarian identify trends that visual estimation alone would miss.

Arowanas are notorious jumpers. In the wild, they leap above the waterline to snatch insects and small prey from overhanging branches, and this instinct does not disappear in captivity. A secure, well-fitted tank cover is not optional — it is the single most critical safety accessory for any Arowana setup. More Arowanas are lost to jumping out of uncovered or poorly covered tanks than to any disease.

The cover must be heavy enough or securely latched enough that the fish cannot dislodge it. A full-grown Arowana can generate significant upward force during a jump, and lightweight screen tops or loosely placed glass lids are insufficient. Many keepers use custom-cut acrylic or polycarbonate panels with latching mechanisms or weighted edges. The cover should be tight-fitting with no gaps wider than half an inch along the edges or around equipment cutouts.

Ventilation is a design consideration that balances safety with gas exchange. A completely sealed top can trap heat and reduce oxygen exchange at the water's surface. Incorporating small ventilation slots or mesh panels along the back edge of the cover — away from the areas where the Arowana is most likely to jump — allows air circulation without creating an escape route.

Power outage preparedness is an often-overlooked safety category. A battery-powered air pump provides emergency oxygenation during electrical failures, which is critical for a large fish with high oxygen demands. Uninterruptible power supply units rated for aquarium use can keep essential equipment — filters, heaters, air pumps — running for several hours during an outage. In regions with frequent power interruptions, a small generator dedicated to the aquarium setup is a worthwhile investment for protecting a valuable and long-lived fish.