Everything You Need to Know about Jellyfish in Aquarium

White cool jellyfish found in aquariumJellyfish are simple animals that live in a jar, but they’re not as easy to manage as you might think. They need a water filter, and the air supply can be sensitive to chemicals in the water and high levels of nitrates and prefer not to be moved. If this is your first time keeping jellyfish, you should probably buy some from an aquarium supplier instead of catching them yourself.

Jellyfish Aquarium Setup

Aquarium: A good-sized aquarium works best because jellies are very active swimmers, but a smaller one can be used if you have only a few jellyfish. Remember that they double in size every day for their first few weeks and need more room as they grow.

Aquarium heater: A heater is necessary to keep the water between 50°F (10°C) and 86°F (30°C). It’s best to buy one especially for your aquarium; place it on the side against a wall or put it under gravel at the bottom of the tank.

pH test kit: A pH between 6.8 and 8 is best, so use this kit to measure it.

Sand or gravel: 1 to 2 pounds will be needed.

Aquarium filter: You will need an aquarium filter that can handle 30 gallons (113 L) per hour, plus extra for filter bacteria if you have a lot of fish in the tank. Water turnover rate is more critical than filter size or strength for jellyfish, so buy an inexpensive one.

Feeder Shrimp: Feeder shrimp are sold at aquarium stores and sometimes in pet stores that sell fish. A few feeder shrimp will provide food for your jellyfish when they are tiny, but you will have to buy several shrimp every few days when they get bigger. Don’t keep feeders in the aquarium with your jellyfish; store them in a closed jar instead.

Aquarium thermometer: A thermometer is necessary for keeping jellyfish.

Net: Use this net to catch jellies when you feed them.

Can You Keep Jellyfish in an Aquarium?

With the right aquarium environment, yes, you can keep jellyfish in the aquarium, but you should know that the jellyfish will not be easy to care for. They need a lot of special care and precautions. Keeping jellyfish in an aquarium is not something that beginners should do, but advanced aquarists may find it exciting and enjoyable.

Can you put a jellyfish in an aquarium with other fish?

In a tank with fish, jellyfish will quickly become food for the other occupants. If you want to keep jellyfish in your aquarium, the tank must be entirely jellyfish-proofed. People tend to do this by putting air pumps and oxygen containers on both sides of the glass. Jellyfish are sensitive to chemicals in the water and high levels of nitrates, so it’s essential to do this.

What kinds of fish can live with jellyfish?

Jellyfish do fine with other invertebrates such as starfishes and sea cucumbers. You cannot keep jellyfish with any of the many species of fish that will eat them. If you want to keep jellyfish along with some fish, choose a species that will not fight for territory and is too big for your jellies to eat.

What Types of Jellyfish Can You Keep in My Aquarium?

The only types of jellyfish you should try to keep as pets are moon jellies. These are the easiest to care for, and they reproduce in captivity. However, any size or species of jellyfish can become dangerous. It would be best to never catch a jellyfish from the wild because you will have no idea what conditions it needs to survive.

Can I Keep Two Jellyfishes in My Aquarium?

You shouldn’t keep two jellyfish in one aquarium because they are very aggressive, especially when eating. If you find jellyfish in your tank with another one already there, the best thing to do is to net them out of the water and take them back to the store where you bought them.

How To Care For Jellyfish In An Aquarium

You need to know a few things about caring for jellyfish in an aquarium. They need a constant supply of clean water with no ammonia or nitrates ( chemicals produced by fish ). They also need a steady supply of oxygen and a carefully regulated water temperature.

What are the Aquarium Tank Requirements for Jellyfish?

Jellyfish aquarium should be cylinder-like. Jellyfish need a tank of at least 30 gallons, but larger is better. Jellyfish do not require an additional filter because they catch small food particles in their long tentacles. It’s possible to buy a jellyfish tank with a built-in filtration system. The lid should be strong enough to resist jellyfish stings, and the top of the tank should have a screen for oxygenation. You’ll need an aquarium heater that can hold up against saltwater. You also may want to purchase an automatic fish feeder.

How To Feed Jellyfish in An Aquarium?

Aquatic jellyfishes do not require food, but if you want to feed your jellyfish and watch them eat it, you should provide them live shrimp twice a day. If there is no natural food for jellyfish in the tank, they will die.

What Types of Food Can Be Fed To Jellyfish?

Jellyfish cannot be fed as typical fish are fed. They have special food requirements, and you must not provide them with anything else. Most jellyfish only eat live shrimp.

Care Guide for Aquarium Jellyfish

  • Jellyfish tend to die if they run into trouble. Stings from other jellyfishes or even humans can cause their death. You must be hyper-cautious about protecting your jellyfish from any danger.
  • Every day you should check the tank to make sure everything is working correctly, and once a week, you should change 10% of the water. Every three months, change half of the water in the tank. It would help rinse off rocks for your jellyfish that are not coming from an ocean because rocks can become toxic under aquarium conditions.
  • Every six months, you should check all equipment and ensure nothing is broken or worn down. You also need to change the water in the tank and rinse off rocks. If there are no natural rocks for your jellyfish and they’re contained in a plastic tank, then you don’t need to change the rocks.
  • It would help if you only fed your jellyfish live shrimp, and you must not feed them anything else. Most jellyfishes will only eat live shrimp, but if there are no shrimp available in the tank, they will die.
  • You should never clean your aquarium with any form of soap or other chemicals. This is because even a tiny amount of a harmful chemical can kill your jellyfish.


Jellyfish are very beautiful and exciting, but they are not for everyone. The tank must be set up correctly and taken care of properly, or you may find yourself with a dead jellyfish on your hands. The constant clean water supply is crucial for caring for jellyfish. You also need to check all equipment and feed them live shrimp regularly. If you do this for your jellyfish, they should survive for several years in the aquarium.

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