
BOO! For some reason, a lot of people are surprised when they see a black fish with big, bulgy eyes- only to find out that it’s actually a type of goldfish.
Black Moor Goldfish are fancy creatures are social, easy to care for, and have a shade of black that curbs a mysterious appeal. Read on to discover.
Last updated: 2/4/18.
Here’s how to care for your Black Moor Goldfish…fast and easy:
(Note that this care guide is for educational purposes only. I cover the majority of what you need to know to raise a happy fish, but that doesn’t mean I cover everything you could know. You could probably find a whole textbook dedicated to Black Moors. This guide isn’t intended to treat any fish condition. Always use your own best judgment when reading and caring for your fish.)
THE BLACK MOOR
- Care level is EASY. Black Moors make an excellent choice for beginners and fish hobbyist newbies. Great choice for a first-time fish owner.
- Mature size is about 8 inches. These fish grow many times their own size, so purchasing a larger tank at the start is a good idea. It’s cheaper and more cost-effective to get a large tank and let the fish grow into it, rather than buying a small tank now and getting a large one later
- Black Moors eat both PLANTS and ANIMALS. They’re omnivores. Variety is key. Their staple diet should be goldfish flakes or pellets. Protein should be high in content, but limited to about 30-35% of the diet. Check the guaranteed analysis on the container to see the breakdown of the food. Tetra is a leading brand in the fish-care industry and makes an excellent staple goldfish foodthat many aquarists recommend. Their formula is complete and balanced, with the correct amounts of protein, fat, and other necessary ingredients- pretty much all the hard work is already done for you. Black Moors can also be fed lettuce, peas, and zucchini on occasion. I recommend to stay away from live or frozen treats due to the possibility of parasites. If you can find a non-parasitic live food source for goldfish, you can feed it as a treat. Feed your fish as many flakes or pellets as he’ll eat without letting any go to waste within 3 minutes, at most twice a day. Keep your fish hungry. A hungry fish is a happy fish. Don’t overfeed.
- Black Moors are SOCIAL FISH. They are great tank-mates with other goldfish and peaceful fish. However, due to their telescoping eyes, they may be too slow to react to food and other fish may snatch it up before they get a chance. Therefore, housing multiple Black Moors together provides equal competition and make a perfect bunch. Other telescoping fish can be housed with Black Moors as well, such as the funny-looking Bubble Eye Goldfish.
BLACK MOOR AQUARIUM SETUP AND MAINTENANCE
- An aquarium size of no less than 20 gallons should be used for 1 Black Moor. The minimum size is 10 gallons- you shouldn’t go lower than this. As always with fish, the larger the aquarium, the better. Also, please don’t house your goldfish in a fish bowl. These bowls are usually 1-3 gallons and don’t provide enough room for the fish to grow and freedom to swim. When purchasing a 20 gallon or larger tank, you may have options of having it “20 tall” or “20 wide.” This basically means if you want the tank to be taller or wider, one or the other. The volume of water remains the same, it’s just the shape of the tank that varies. For Black Moors, choosing a wider tank is preferred. This allows greater horizontal swimming room and oxygen exchange. If you plan on adding additional Black Moors in the same tank, add an additional 10 gallons for every 1 fish.
- Aquarium FILTRATION is critical. Black Moors are messy eaters and produce plenty of waste. You’ll have several options to choose from between filters, such as power filters, also known as hang-on-back (HOB) filters, internal filters (not recommended), undergravel filters (UGF), and canister filters. Whatever filter you choose, look at the gallons per hour (GPH) rating on the package. This is simply a measurement of how many approximate gallons of water the filter cycles per hour. Since power filters are the most common filter, let’s go through a simple example. Take your tank size and multiply it by 10. That’s the minimum GPH rating you should have.
So let’s say your tank is 20 gallons. Take 20 x 10. That’s 200. Your filter should cycle at least 200 GPH. This will most likely be way over the recommended tank size the package says (it’ll probably say a 200 GPH filter is used for a tank much larger than your 20 gallons), but do your fish a favor and go for it. This is a basic rule of thumb in fish communities. The package isn’t all that accurate in recommending a proper filter. Plus, you can never have enough filtration. Keep that in mind.
- A 25% water change should be done every week. This is just as important (if not more), than your aquarium filter. How do you perform a water change? Easy. Let’s go through the steps.
1. First, remove 25% of the water in the tank (you don’t need any fancy tools, just estimate). The best way to do it is to use a gravel vacuum to clean the gravel. This will remove dirt and waste caught on the gravel bed and remove water at the same time. It’s not necessary to remove your fish from the tank, as long as you don’t cause too much disruption. Collect the water into any container.
2. After you’ve collected about 25% of the dirty water, dump it. Try to remember how much water is in your container before dumping it.
3. Scrub the sides of the tank (on the inside, get your hands in there!) with a soft scrubber. Wipe down the filter and aquarium hood. Clean any plants or decorations if needed. It’s important to only use the water in the tank to clean. Don’t use tap water or any solutions (like Windex).
4. After a quick scrubbing session, grab that container from earlier and fill it up with tap water to around the same level that you filled it to. Now you’re going to treat it. Treated water is just water that’s had its harmful chemicals removed. You can make your own treated water at home using a water conditioner (you’ll save a lot more money than going out to buy treated water every week). Again, Tetra also makes a trusted water conditioner called Tetra AquaSafe, which works directly with the tap water from your sink. You basically pour a few drops into the water and it’ll magically make it safe for your fish. Read the directions to find out how much to drop.
5. After treating the water, pour it back into the tank. Be sure it’s close to the same temperature as the water inside the tank. Warm it up with a heater or let it cool if it’s too great of temperature difference. For some geeky fish talk, what you just did is called a “partial water change.” This should be done weekly for Black Moors since they’re messy eaters.

“Moor.” Thanks to the courtesy of Woodlouse via Flickr for providing this photo.
- WATER FLOW is important to oxygenate the water. Ripples and water agitation “adds” oxygen into the aquarium. Use airstones and bubble bars powered by an aquarium pump to produce water movement. Some power filters also have a “waterfall” as an outlet for the water to fall back into the tank after being filtered. This produces excellent surface agitation for oxygen exchange.
- Utilizing an AQUARIUM HEATER is a necessity. Black Moors should have an aquarium water temperature between 71-74F (21-23C). They’re known to be hardy goldfish and can withstand a wide temperature range, however that doesn’t mean they’re not stressed in doing so. Can you stand 30F weather? Sure you can. But are you stressed in doing so? Probably. Let’s not do the same to your fish. Get an aquarium heater. Preferably an automatic aquarium heater, which means it has temperature setting with automatic heating. This way, whenever the temperature drops below your set temperature, it’ll automatically heat until it reaches it, then automatically shut off until it drops again. Kinda like how your A/C works.
- Use LIGHTING to keep a proper day-night cycle. Black Moors should have at least 8-12 hours of daylight. This can be done using natural light if it’s bright enough, however, keep the fish tank out of the sun. If natural light can’t be used, then aquarium light bulbs should be implemented into the hood of your fish tank. The bulb color should be warm white. It should look like your typical living room light- white light with a yellow tint.
- Get a THERMOMETER to keep tabs on the water temperature. You’ll need this to make sure your aquarium heater is working correctly and for weekly water changes. I recommend the thermometers that stick inside the aquarium (that actually touch the water). The strips that stick on the outside of the tank are highly inaccurate…sometimes up to 20F off!
- Keep sharp objects AWAY from your Black Moor. Their bubbly eyes are extremely vulnerable to sharp objects in the tank, including plants and decorations. Use smooth, leafy plants and ornaments with no rough or sharp edges for aquascaping.
Phew. Well, that about sums it up. Fast and easy. We touched on the major points on how to raise a happy, healthy, bubbly-eyed Black Moor Goldfish. Okay, maybe I got a little carried away there and it wasn’t as short and “fast” as I thought it’d be. But hopefully you learned a thing or two from my rambling. Now get out there and adopt one of those poor fishes in those overstocked tanks and be a proud foster parent. Let’s do it! All hands in the middle! Hip-hip…WHO’S THE BEST FISH OWNER IN TOWN? I AM.

“The Black Moor.” Thanks to the courtesy of Riyad Youssef via Flickr for providing this photo.
All images licensed under CC BY 4.0.
Questions? Comments? Running out to your LFS (fancy aquarist talk for Local Fish Store) to become a proud owner? Already a proud owner? Share your experiences below.