Standing in the aquarium section at Petco last weekend – you know, the one where half the fish look stressed and the water’s always slightly cloudy – I watched this kid, maybe sixteen, grab a black moor and ask the employee if it’d be okay in a fishbowl. A fishbowl! The employee just shrugged and said “sure, goldfish are hardy” while ringing up the sale. I literally had to walk away before I said something that would’ve gotten me banned from the store.
Look, I get it. Black moors are sold everywhere as beginner fish. They’re cute, they’re cheap, and pet stores act like they’re basically aquatic houseplants. But here’s what nobody tells you – these fish are actually one of the most challenging goldfish varieties you can keep. Those bulging telescope eyes that make them so distinctive? They’re also what makes them incredibly vulnerable to just about everything.
My first black moor disaster happened about six years ago. I’d been keeping regular goldfish in my classroom tank for a while, figured I knew what I was doing, so I picked up this gorgeous black moor from a local fish store. Named him Cosmos because, well, those eyes looked like little black planets. Set him up in what I thought was a generous 30-gallon tank with some nice decorations I’d collected – piece of driftwood, some plastic plants, a castle because the kids loved it.
Three months later, Cosmos had scratched both eyes, developed what looked like swim bladder disease, and spent most of his time listing to one side near the bottom of the tank. The vet bill was more than I’d spent on the entire tank setup. Turns out I’d basically created an obstacle course designed to injure a nearly blind fish. The guilt kept me awake for weeks.
That’s when I really started researching these fish, and honestly? Everything I’d been told was wrong. Black moors aren’t just goldfish with funny eyes – they’re specialist fish that need completely different care. Their vision is terrible, they’re slow, they bump into everything, and they produce waste like tiny underwater garbage factories.
The tank size thing makes me crazy because everyone gives different answers depending on what they’re trying to sell you. Pet store employees will swear 20 gallons is plenty. I’ve seen websites claim 10 gallons works for a single fish. Complete nonsense. I’ve kept black moors in tanks ranging from 20 gallons up to my current 75-gallon setup, and anything under 40 gallons is basically fish torture. They grow huge – my current three are all over six inches – and they’re messy in ways that’ll shock you if you’re used to other fish.
Water quality becomes this constant battle with black moors. I thought I understood goldfish waste production from keeping regular varieties, but black moors are on another level entirely. My original filtration system, which worked fine for other goldfish, couldn’t handle a single black moor. I was doing water changes twice a week and still fighting ammonia spikes. Had to upgrade to a canister filter rated for a tank twice my size, and even then I’m religious about maintenance.
Temperature stability matters way more than most people realize too. Regular goldfish handle temperature swings pretty well, but black moors react to even minor changes by developing swim bladder problems immediately. I learned this during an unusually hot week in September when my classroom tank hit 78 degrees. Came in Monday morning to find two fish floating sideways, completely unable to control their buoyancy. Now I actually run a small chiller during warm weather, which my principal thinks is ridiculous, but healthy fish are worth the electricity bill.
Feeding these fish properly requires more patience than I sometimes have on a rough teaching day. Those telescope eyes make them impossibly slow at finding food. In my early attempts at community tanks, I’d dump in flakes and watch the regular goldfish demolish everything while the black moors swam around confused, bumping into decorations, barely getting any food. I tried feeding more, thinking they’d eventually get their share, but that just polluted the water faster.
Now I use feeding rings to create separate areas, or honestly, I hand-feed them using long tweezers. Sounds excessive, but it’s the only way to ensure they get adequate nutrition. My current three fish have learned my routine – they actually come to specific corners of the tank at feeding time because they know that’s where their food appears.
Most commercial goldfish foods are garbage anyway. I’ve probably tested every brand available at local stores over the years, and most are loaded with fillers that cause digestive issues. The cheap flakes dissolve immediately, creating this nasty cloud that fouls the water. I feed primarily sinking pellets now, supplemented with blanched peas and zucchini. Way more expensive than flakes, but the improvement in fish health and water quality is dramatic.
Tank decoration becomes this whole safety evaluation process with black moors. Anything with even slightly sharp edges is dangerous. I learned this after my second attempt, a fish I called Hubble, scratched his eye on what looked like perfectly smooth driftwood. Now I literally run my hands over every decoration multiple times before adding it to any tank. If it feels rough to my skin, it’s too dangerous for telescope eyes.
I switched to silk plants exclusively – never plastic, which can have sharp edges – and carefully selected river rocks. Sand substrate works best because goldfish love sifting through it naturally, and it won’t injure their eyes when they root around for food. Just be prepared for your filter to work harder dealing with the fine particles.
Lighting is another consideration I never expected. Those bulging eyes seem more sensitive to bright light than normal fish eyes. I run my tank lights on lower settings and provide plenty of shaded areas with floating plants. Direct sunlight through windows stresses them significantly – discovered this when I moved my home tank to a brighter location and noticed the fish hiding constantly.
Disease prevention becomes absolutely critical because their eye structure makes them prone to infections. I maintain a quarantine tank religiously now, something I used to skip with hardier fish. Every new fish gets minimum 30 days isolation, regardless of where I bought it or how healthy it looks. I’ve caught bacterial infections, parasites, and stress-related issues during quarantine that definitely would’ve spread through my main tank.
The biggest myth about black moors is that they make good community fish. They absolutely don’t work in mixed tanks unless you’re prepared to completely modify your care routine. Faster goldfish will outcompete them for food every time and may accidentally injure them during normal swimming. I tried mixed tanks multiple times before accepting that black moors need dedicated setups.
My current 75-gallon tank houses exactly three adult black moors, which sounds like overkill until you see how much space they actually need to navigate safely. Water quality stays stable, each fish has room to swim without constantly bumping into tankmates, and I can monitor individual health easily. They’ve thrived in this setup for over three years now, showing vibrant coloration and the graceful swimming that makes telescope goldfish so appealing.
Breeding attempts taught me even more about their specialized needs. The telescope eye trait causes developmental problems in offspring – many don’t survive to adulthood, and survivors often have worse vision than their parents. I tried twice with limited success and decided it wasn’t worth the stress on the adult fish.
The reality nobody wants to admit is that black moors require dedicated care from someone willing to accommodate their special needs. They’re not beginner fish despite what every pet store claims. They’re specialist animals that reward proper care with years of unique personality and beauty, but if you’re not prepared for higher costs, extra work, and specific requirements, choose a different goldfish variety.
When I watch my three black moors swimming peacefully in their properly designed environment, all the effort feels worthwhile. They recognize me at feeding time, have distinct personalities, and display that graceful movement that drew me to them initially. But it took years of expensive mistakes, countless hours of research, and ongoing dedication to create conditions where they actually thrive instead of just surviving.
Jordan’s home tanks started as a way to teach his kids about nature—and ended up teaching him patience. Between client work and bedtime chaos, he finds calm trimming plants and watching fish. Family life, design, and algae control all blend in his posts.
