Why My Arowana Staying in One Spot – 2026

I am completely exhausted right now.

I just spent seven agonizing hours scrubbing thick green algae off a dozen massive display tanks at the shop, my boots are completely waterlogged, and my inbox is an absolute disaster zone. Frantic beginners constantly email me demanding to know exactly why my arowana staying in one spot like a lifeless log at the bottom of their expensive glass box.

It happens to literally every single newcomer in this hobby. You spend hundreds of hard-earned dollars on a majestic monster fish that is biologically designed to prowl the water’s surface like a sleek, silver dragon. Then you just stare blankly at the glass while your prized pet sulks miserably in a dark, dirty corner.

Let me tell you about a brutally embarrassing Sunday morning back in July 2014 when I actually thought I was a certified aquatic genius. I bought a gorgeous, wildly expensive juvenile silver arowana named Bullet, and I impatiently dumped him straight into a poorly cycled grow-out tank simply because I was way too lazy to wait another week. I felt completely sick to my stomach and horribly ashamed when I found him pinned to the bottom glass the next morning, gasping desperately because an invisible toxic ammonia spike had chemically burned his delicate gills overnight.

He survived, barely. Guilt. It absolutely haunts me every single time I look at a plastic water testing kit.

The actual reason why my arowana staying in one spot today

When panicked people aggressively ask me why my arowana staying in one spot, I always tell them to take a deep breath and immediately test their water parameters. Not tomorrow after work. Now.

Arowanas are obligate surface dwellers that possess upward-facing mouths specifically evolved to snatch heavy, crunchy insects right off the water’s surface tension. If your massive top-feeding fish is pinned tightly to the gravel or hiding motionlessly behind a rotting piece of driftwood, it is completely terrified or physically suffocating. Hypoxia.

Low dissolved oxygen is a massive, completely silent killer in large predatory setups. When your aquarium water gets way too warm or your surface agitation is utterly pathetic, the massive fish literally cannot pull enough oxygen over its damaged gills to survive. You can read about how temperature physically impacts oxygen capacity if you really want a massive headache Wikipedia/Oxygen saturation.

Your expensive fish will just sit there in the dark. Gasping. Waiting to die.

Check your incredibly disgusting water

Another massive, extremely common reason why my arowana staying in one spot revolves heavily around invisible toxins like ammonia and nitrite. You feed these giant, hungry fish massive amounts of heavy, messy proteins like thawed shrimp and thick pellets. That rotting, uneaten waste builds up incredibly fast in the substrate if you blindly skip your weekly maintenance routine.

Toxic. When sharp ammonia spikes in a closed system, it violently burns their sensitive eyes and gills, forcing them to clamp their fins tightly and sink to the absolute bottom of the tank in pure, unadulterated misery. If you are legitimately wondering why my arowana staying in one spot this week, you seriously need to ask yourself when you last hauled a heavy, sloshing bucket of dirty water to the kitchen drain.

Arowanas are surprisingly fragile when it comes to sudden pH crashes, too. If your water gets too acidic because you never vacuum the filthy gravel, they will shut down completely. Clean.

My brutally unpopular opinion on tank sizes

Here is a strong opinion that gets me absolutely screamed at by stubborn, cheap guys on local internet fish forums. Keeping an adult arowana in anything less than a 250-gallon tank is flat-out, undeniable animal abuse. Period.

These wild fish routinely grow to over three feet long in their natural river habitats and desperately need massive amounts of open swimming space just to physically turn their long, stiff bodies around. If you stubbornly stuff a rapidly growing monster into a cramped 75-gallon glass box, its internal organs will literally crush against each other while its spine slowly, painfully deforms. It makes me so incredibly angry when corporate pet stores happily sell these giants to clueless beginners with tiny living room setups just to make a quick buck.

If they physically cannot turn around without smashing their face into the glass, they will just stop swimming entirely. They completely give up. That is exactly why my arowana staying in one spot is a depressing question I hear constantly from people who refuse to upgrade their ridiculously tiny tanks.

Tank mates from absolute hell

Sometimes the water chemistry is completely pristine, but the arowana is just completely traumatized by its awful roommates. People lazily mix highly aggressive, territorial cichlids with their arowanas, foolishly expecting everyone to just get along peacefully like a cartoon. They do not.

A massive, angry oscar or a mean jack dempsey will relentlessly bully a shy juvenile arowana until the poor thing cowers in the darkest corner of the tank just to avoid being violently shredded. Stress kills fragile fish faster than almost anything else in this wildly frustrating hobby. If your arowana is completely terrified of getting bitten, it will hide completely motionless in the shadows.

Arowanas naturally swim at the top of the water column, so placing them with aggressive surface-feeders is a recipe for an absolute bloodbath. They constantly compete for floating food and territory until the weaker fish finally gives up. Defeated.

You have to match their individual temperaments perfectly if you want a peaceful community. If you desperately need some high-quality gear to permanently separate aggressive tank mates before someone gets murdered, Check out our fish care supplies here. Separation saves lives.

Stop staring and do some actual work

Guessing blindly about why my arowana staying in one spot is a total waste of time if you stubbornly refuse to do basic diagnostic work. Grab a liquid test kit right now. Check the water temperature.

Figuring out why my arowana staying in one spot is incredibly easy if you just observe their breathing rate closely and look for shredded fins. Fixing the underlying problem takes real, dedicated patience and usually a massive, back-breaking water change. Clean, fresh water works absolute miracles.

My knees are absolutely throbbing in pain right now and my hands smell strongly of old, rotting filter sludge. Stop staring blankly at the glass and go do some actual tank maintenance. Good luck.