New to Keeping Jellyfish

How to Keep a Jellyfish

Yes. Jellyfish can easily be kept in captivity these days because of massive advances in technology. At one point, we had no clue on how to keep jellyfish. We were confused why they didn’t thrive in a normal box aquarium. We were confused that they didn’t eat normal food. There was a lot to learn, but now, after years of research, we know better. We learned that jellyfish tanks need a particular flow, and a particular shape of tank. We learned that jellyfish have small mouths and can only eat a specific size of food. We learned how to control temperature in an aquarium, and we learned how to filter the water easily.

These days, keeping jellyfish is easier than ever. You might be used to seeing fisheries in China raise the flame jellyfish, or see the Monterey Bay aquarium keep massive sea nettles. But what you may have just learned is that you too can keep jellyfish!

Is it Easy to Keep Jellyfish?

Nowadays, yes. You no longer need to build your own aquarium, you can simply purchase one from us! We offer multiple varieties of tank designs, ranging from our smallest tank being only 2 liters of water to our largest being 10 gallons.

These days, feeding jellyfish is also easier than ever. You have the options of dry food, live food, and even frozen food to care for your jellyfish. No longer do you have to have massive complex machines from out of a science fiction movie!

So in that respect, keeping jellyfish is easy. In fact, I would argue that keeping jellyfish is easier than keeping your average saltwater tank. It’s more difficult than freshwater, certainly, because you have to pre-mix aquarium salt into RODI (reverse osmosis deionized) water. That mixing process is possibly the most difficult aspect. We will cover how to mix water in our section devoted to water, so you’ll learn fairly quickly that mixing up a batch of saltwater isn’t difficult at all!

The other difficulty in keeping jellyfish is ensuring that the water they live in is clean. You want to avoid spikes in water chemistry, and you want to keep the water fairly stable. This means that on a regular basis, at least once a week, you want to change some of the old saltwater in your aquarium with fresh saltwater, to keep the tank from getting too mucky.

So think of it this way. A jellyfish may be harder than a goldfish, but it’s actually very easy if you compare it to keeping your average fish tank. You just have to make sure that the temperature of the aquarium is stable, that the salinity in the water doesn’t spike suddenly, and that you clean your aquarium on a regular basis. If you master these three cornerstones of jellyfish keeping, you’ll soon be an expert just like us here at Jellyfish Aquarium!

Of course, it may sound like I’m tossing gibberish at you right now. But by the end of this article, you should feel confident and ready to tackle even the most intimidating jellyfish out there! Mind you, seeing as they’re body composition is over 95% water, that might not be such a difficult task…

What Do I Need to Know?

Jellyfish keeping can be broken down into three easy parts. Keep the water clean and stable, feed them good food, and clean the tank once a week. If you do these three tasks, your jellyfish will live a happy life. Of course, this may not mean much without understanding what each part means. That’s why I set out to write this blog, to teach you how to take care of your jellyfish to the very best of your abilities. 

The first task we will tackle is water. Then, once you’ve learned about water chemistry (which sounds far more intimidating than it is) and salinity levels, we can focus on feeding your jellyfish. After you’ve learned the two most crucial aspects of jellyfish care, you can learn about how to clean a jellyfish tank. This is far easier than you’re probably expecting. If you master water, food and cleaning, you’ll realize keeping jellyfish is surprisingly easy!


Jellyfish bodies are composed of over 95% water. What does this mean though? For us, it means that to keep the jellyfish healthy, we have to keep the water they live in ‘healthy’.

The first step to keeping our water healthy and clean is to use the right type of water. With most fish, you don’t have to worry about the minerals in the water, and you can simply use a dechlorinator from your local pet shop to keep your fish healthy. With jellyfish, they take it a step further. Jellyfish are very sensitive to trace minerals in tap and well water. So thus, jellyfish need a special type of water known as RODI (reverse osmosis deionized) water. You can simply use RO (reverse osmosis) water, but RODI water is what’s preferred. Be careful though, as simply picking up water from the store can be a bit tricky! Sometimes, they slip minerals into the water, so be sure to read the label of the bottle that you’re using. Consider it calorie tracking for your jellyfish! But if you really want to be safe, just use RODI water from a water shop or, better yet, buy your own RODI machine and use it at home. They’re easy to set up, and will save you plenty of money in the long run.

Now, jellyfish don’t just live in RODI water. They live in saltwater. This means we have to mix salt into the RODI water before we can use it in our aquariums. Unless specified, all our jellyfish live at a salinity of 30 parts per thousand (ppt), or 1.0226 specific gravity (sg). You can use a refractometer, hydrometer, or my preference a digital refractometer to read the salinity levels of the water.

The H2Ocean Refractometer is a fantastic tool for the budding aquarist.

Mix salt into your water as per the package instructions, and take readings with your chosen method of reading salinity, and make sure it reads 30ppt or 1.0266sg before using it in your aquarium. You’ll want to mix the salt into the water at least the night before a water change, and stir it up. This is to ensure the salt is thoroughly dissolved in the water before you put it in your jellyfish tank. We noticed that if the salt isn’t full dissolved, the salt can stick to the jellyfish, and they can take on a wonky shape. This doesn’t mean your jellyfish is harmed, but they will look a bit odd.

Now you can’t just add in jellyfish after you mix up your water and your tank is filled. You need to cycle your tank first! To learn more about cycling a tank, take a look at our blog here!

Now, once your jellyfish are in the water, you need to make sure that there are no spikes in water chemistry. But what do we mean by water chemistry? By water chemistry, we mean three different byproducts of waste being broken down. I discuss it more in the water cycling blog, but essentially these three byproducts can be very harmful to your jellyfish. You need them to cycle the tank, but by the time it’s finished cycling and you have jellyfish, you shouldn’t be reading any ammonia or nitrite. When jellyfish are in the tank, these readings should be 0. If it’s anymore, change the water in your tank as soon as you can. Nitrates however is a different story. Though 0 nitrates is ideal, you can get away with nitrates climbing to 20. But beyond that, it will start to affect the jellyfish’s health for the worse. So thus, try to keep the water chemistry readings down, and your jellyfish will be very healthy!

The API 5in1 Test Strips are a fantastic tool for reading the water chemistry

But how do you read water chemistry? Well, there are some very complicated methods, but the easiest is to use the API 5in1 strip that we sell on our website, and dip it into the aquarium. When you pull it out of the water, it should give nearly instantaneous results. Though they may not be the most accurate, they are the easiest. And honestly, using an easy method and consistently testing is better than using a complicated method and avoiding testing the water at all.

And that’s it! Use RODI water mixed with aquarium salt. Then, cycle your tank before adding jellyfish, and you’ll never have to cycle it again! One a week, or once a day if you can, check the water chemistry in your tank and see how it looks. It sounds like a lot, but in truth it’s quite simple.


The next cornerstone of jellyfish care is feeding. Specifically, what do you feed your jellyfish? The answer is, there’s a variety! The most common food we sell is Jellychow. Jellychow is essentially freeze dried zooplankton. We sell it with a small scoop, which you can use to measure out how much you feed your jellyfish. We encourage you to feed only half a spoonful once per day. This is because though the food is convenient, it can really dirty the water.

We offer Jellychow in 25 gram packets and 50 gram packets

So if you want to avoid dirtying the water, what food should you provide? The best answer is live. We sell brine shrimp eggs that you can hatch, and use the freshly hatched brine shrimp to feed your jellyfish. We also have a blog on jellyfish, so be sure to check it out here!

The artemia hatchery is a fantastic tool to hatch brine shrimp eggs

But brine shrimp alone isn’t the best diet. So what do you do? At jellyfish Aquarium, we came up with an easy feeding schedule. Every day, we feed our jellyfish freshly hatched brine shrimp except on the day before a water change. On the day before a water change, we feed our jellyfish Jellychow. This allows our jellyfish to have a healthy, balanced diet, and we can keep the water clean easily!

By feeding a mixture of fresh and dry food, our jellyfish are very healthy and well looked after. 


Cleaning a jellyfish tank is really quite simple. It’s very similar to cleaning a regular fish tank.

The Pro Maintenance kit is the best choice for a collection of jellyfish cleaning supplies

Siphon out the bottom of the tank into a bucket, and replace the amount of water you took out with fresh saltwater that you’ve mixed the night before. We recommend changing about 25% of the water once a week. Be careful when siphoning though, as you don’t want to accidentally suck up your jellyfish! To prevent this, grab the siphon hose, and form a sort of kink in the hose with your free hand. When the jellyfish gets close to the siphon, kink the hose to stop the siphon, and once they’re passed by, you can open the siphon again to continue cleaning. For our visual learners, Aquarium Co-Op has an excellent video. 

Once you’ve finished siphoning, use a scrubbing pad to clean down the sides of the tank. Then, when you’re finished cleaning the inside, use the acrylic cleaning cloth or a soft towel to mop up any water that’s gotten out of the tank. 

Once a month, though, it’s advised to give a more thorough cleaning. This means scrubbing the inside of the airline tubing with a pipe cleaner, and cleaning the sponge in the back of the filter in dirty tank water. It may seem odd rinsing the sponge in the dirty tank water, but it’s because you don’t want to lose any of the beneficial bacteria that’s built up in the aquarium. So simply take out the sponge and rinse it in the dirty tank water, and put it back in the tank. It’s as simple as that!

The whole process usually takes between half an hour to an hour, depending on how dirty the tank is and if you’re doing a thorough clean.

Kits and Packages

The quarterly supply kit is great for all jellyfish keepers, new and experienced alike.

If you’re interested in getting a jellyfish but the amount of products is overwhelming, Jellyfish Aquarium has a couple of options to help you out.

The kit I recommend to anyone buying jellyfish is the quarterly supply kit. The quarterly supply kit includes all the necessary products you would need to keep your jellyfish healthy. The kit includes aquarium salt, jellychow, pristine and chemipure blue nano.

Aquarium salt and jellychow are fairly self explanatory, but I haven’t covered Pristine or Chemipure yet. Seachem Pristine is a fantastic product that can be added the first few days after adding jellyfish to the tank. It provides bacteria to the water that will help prevent a spike in water chemistry, and it seems to benefit the jellyfish in the long run.

Chemipure is a carbon packet that aids in the filtration process. You place it in the filter compartment of your tank, submerged in water. It helps prevent a build of poor water chemistry.

The quarterly supply kit comes in two options, with and without test strips. We do recommend the package with test strips as it gives you the option to check your water quality more frequently. This is especially important in the first few months of keeping jellyfish.

The quarterly supply kit typically lasts for at least 4 months before the supplies run out, and it’s advised to buy from us again.

The other kit that Jellyfish Aquarium encourages you purchase with your tank is the pro maintenance kit. The pro maintenance kit includes all the supplies you need to clean your tank, such as the siphon, the jellything tool, the acrylic cleaning cloth and the algae scrub pad.

All of these pieces of equipment are excellent to use when cleaning your tank.


So there you have it! Those are the three important steps to keeping jellyfish. Mix up RODI water and aquarium salt, feed your jellyfish healthy food, and clean the tank once a week. If you master these three aspects of jellyfish keeping, your jellyfish will be healthy and live a (relatively) long life!

Beautiful Brine Shrimp!

How to Hatch, How to Feed

What are Brine Shrimp?

You may have heard of brine shrimp before. Maybe from an aquarium-loving friend, or through poking about online. You could be like one of my friends, who found the brine shrimp aquarium in Animal Crossing: New Horizons. Or, most likely, you knew about (or maybe kept!) Sea Monkeys as a child! That’s right, brine shrimp are more often known by their other name, Sea Monkeys! But, what are they?

Brine shrimp (Artemia Salina) are a group of tiny crustaceans that are known to be farmed in Great Salt Lake, in Utah. They are hatched from eggs, which can be purchased from us here:

They are incredibly small, reaching only a maximum of 15 millimeters in length. Brine shrimp in the aquarium world are highly sought after, as they are incredibly nutritious and a fantastic source of food for jellyfish.

Why Hatch Your Own Brine Shrimp?

Brine shrimp are some of the most nutritious food for jellyfish, and all aquatic life. They are available in many forms, ranging from being a crucial ingredient in dried food all the way to being available in frozen cubes. However, Jellyfish Aquarium prefers to use freshly hatched brine shrimp, and encourages you to do the same. Why? Because of water.

But it’s not just water quality that we’re speaking about this time. The reason Jellyfish Aquarium uses live brine shrimp isn’t just about nutritional content, but also because live brine shrimp stay in the water current for a longer period of time. Dried flakes and frozen brine shrimp settle to the bottom of the tank quickly, and thus are more detrimental to the water quality in the tank. Hatching your own brine shrimp prevents this though. Hatching fresh brine shrimp allows the brine shrimp to swim in the tank water, and thus be more easily eaten by the jellyfish.

The other benefit is that the freshly hatched brine shrimp are small enough to actually be eaten by the jellyfish! Most stores sell adult brine shrimp in frozen cubes, but this is far too large for jellyfish mouths. Remember, jellyfish have absolutely minuscule mouths! The tiniest of the tiny! They simply aren’t big enough for most foods in the ocean! This is why they feed on microscopic zooplankton to sustain themselves. To avoid this, Jellyfish Aquarium uses brine shrimp that’s been hatched within 24-48 hours. The freshly hatched brine shrimp are the perfect size for tiny jellyfish mouths. This means they eat all they need, and they get all the nutrition they need!

How to Hatch Brine Shrimp

After all this talk about how important brine shrimp are, you may be biting at the bit to try your hand at hatching your own! Luckily for you, it’s incredibly easy. In previous years, people have had to use odd and complex ways to get brine shrimp, but these days, you can buy a simple, pre-made brine shrimp hatchery off of our website here: 

However, it’s important to understand a few steps about hatching brine shrimp. For one, you do need a mixture of saltwater and freshwater. At Jellyfish Aquariums, we find the best hatch rate is a 1:1 ratio of fresh to saltwater. So for us, we use about half of a 2L pop bottle of fresh water, and fill the rest up with salt water. Luckily, it doesn’t have to be perfect water. In fact, it’s often easiest to just use salt water that’s left over from after a water change on your jellyfish. Not only that, but you needn’t touch your precious RODI water reserve! For fresh water, you can simply use the water from your tap. It makes no difference to the brine shrimp.

The other important factor with brine shrimp is heat. Most people use a hot light to warm the water of their brine shrimp, and some use a tiny water heater to raise the water temperature slightly. Most find that a consistent temperature is far more important than a consistent light source, and that increases your hatch rate.

Now, there are many ways to set up your own brine shrimp hatchery. One way is to purchase a premade hatchery kit from the link above, or build your own. There are many youtube videos online detailing how to make a brine shrimp hatchery. One video we strongly encourage you to watch is by youtuber Mark’s Aquatics, an english fishkeeper: 

If watching a video isn’t for you, there’s an excellent tutorial online from fishkeeper Solid Gold Aquatics, who has a tutorial here:

After you’ve set up you hatchery and made up your water, you can add your brine shrimp and leave them for up to 48 hours. After you’ve left them for this time, you can drain your hatchery into a coffee filter. This allows the water to seperate from the brine shrimp. Be sure to rinse the freshly hatched brine shrimp with a bit of tap water, or RODI water, it depends on your preference. After the brine shrimp are rinsed and in the coffee filter, you can safely feed them to your jellyfish.

Feeding Time!

Once you’ve hatched your brine shrimp, you may be tempted to simply pour all the brine shrimp into the tank. However, there’s another way that enables you to control how much you feed, and determine how much you need to feed, far more easily.

The best way I’ve found is to take a small cup, and fill it with a bit of water from the jellyfish tank. Then, put the brine shrimp into the cup of tank water. From here, you can take a baster or syringe of some sort, and slowly add brine shrimp from the cup into the water. When you think your jellyfish have eaten enough, you can either save the brine shrimp in your fridge overnight for later, or discard them.

That said, I do recommend adding some nutrient supplements to your brine shrimp after storing them in your fridge. A great product I highly recommend is Boyd Enterprises’ VitaChem. I’ve noticed my jellyfish are healthy, and live longer when I provide them this supplement with brine shrimp (after I’ve left the brine shrimp in the fridge overnight).

Try it Yourself

Though hatching brine shrimp may seem intimidating, it’s easier now than ever. Feeding freshly hatched brine shrimp to your jellyfish ensures they have the best life, and the longest.


If you were interested in any of the products mentioned in this blog, please take the time to look into them more!

Jellyfish Aquarium provides many different sizes of brine shrimp egg packages, and can be found here: 

Jellyfish Aquarium is passionate about getting people to hatch their own brine shrimp. If building your own hatchery is too time-consuming, try buying a premade hatchery! You can purchase a premade hatchery off our website at the link below:

Want to Learn More? Take A Look at Our Sources Below!:


To Feed A Jellyfish

The Question

I remember going to my first convention. It was the first time I had seen customers face-to-face. I was amazed by how many people were there, and eager to answer all of their questions. The grand display tank was filled with large moon jellyfish pulsing around the tank. People adored them. I adored talking to them. As I talked to them, I noticed a pattern. Many of the same questions came up, time and time again. One of the most prominent ones was this:

“But… What do they eat?”

Answering this question, again and again, I just knew I had to write this blog.

The Wild Truth

Itty bitty zooplankton is the beginning of the food chain in the ocean.

Well, first things first, all jellyfish are predators. But jellyfish aren’t just any predator, they’re lazy predators. They’re completely opportunistic. They eat whatever happens to drift by and become entangled with their tentacles. They then they use their oral arms to take the captured prey from their tentacles up to the very center of their bell, and into their (very tiny) mouth. Incidentally, this mouth also happens to be their anus. They’re rather fortunate that they don’t have taste buds.

In the wild, most jellyfish feed on plankton, which is made up of thousands of microscopic species of swimming animals. Jellyfish only eat zooplankton (animals that eat plants or other animals), not phytoplankton (plants that produce their own energy from the sun). Some species of jellyfish, such as the Upside Down Jelly, host symbiotic algae within their oral arms. This algae provides extra nutrition to the jellyfish by producing organic material through photosynthesis. Many species of jellyfish feed on other species of jellyfish. For example, the Sea Nettles feed on Moon Jellyfish.

Jellyfish can also be fed live food, such as baby brine shrimp. This food is highly nutritious and recommended especially for sick or struggling jellyfish. Public aquariums have a full time staff, so they almost always hatch their own baby brine shrimp daily to feed to jellyfish. Depending on the species of jellyfish, sometimes public aquariums also feed the jellyfish rotifers, blended krill, chopped fish, and other foods. Public aquariums rely on these time-consuming foods because they often keep exotic species, breed jellyfish and run experiments.

However, hobbyists can use Jellyfish our dry and live food to suit their jellyfish’s needs.

But What Do I Feed Them?

The daily special? Freeze-dried zooplankton.

We provide a dry jellyfish food specifically formulated for jellyfish made from plankton high in HUFAs (Highly Unsaturated Fatty Acids), which are essential for proper nutrition. We strongly suggest only feeding jellyfish with our recommended food.

Other fish foods that claim to be suitable for jellyfish are often low quality. Follow the feeding guide to properly feed your jellyfish with special care not to overfeed which can cause water quality issues. 

Our high quality Jelly Food includes a small scoop included inside the food bag! For 3-4 jellyfish feed 1/4 scoop of dry Jelly Food in total once per day. Feeding amounts may be adjusted gauging that minimal food is left on the aquarium floor.

During feeding you should mix the dry food in a small container with a small amount of aquarium water, this solution can be dispersed into the aquarium.

Using a container of any sort (I often use a neglected egg cup), I fill it with a bit of water from my jellyfish aquarium using a baster. I wouldn’t take out more than a cup of water from your aquarium for this procedure, as that’s just unnecessary. Then, I pour in a measured amount of dry food into the container of tank water (there is a spoon included in our food packages to do this). I personally just use the spoon itself to mix the food and the tank water, and then leave it. Take this time to thoroughly dry off the measuring spoon if you’ve used it to mix the water. Let the food sit a bit in the water for some time. Not too much to float, and not to much to sink. That’s what you’re looking for.

A large moon jellyfish will need more than a small moon jellyfish.

Once my dried jellyfish food has been prepared, I slowly squirt the food back into the tank with the baster, making certain to avoid any bubbles in the water. Contrary to popular belief, it is best to avoid squirting the food directly at the jellyfish. Instead, squirt the food into the current so that the jellyfish can exercise their tentacles and oral arms. And now, watch. The food should be slowly drifting into the water current. Some will go through the vents, but the filter sponge will take care of that. The majority of the food should be flowing through the current in the tank, allowing the jellyfish to catch it in their tentacles. As time goes on, you may start to notice your jellyfish’s stomach slowly turning a brownish colour as it is filled with food!

Though the jellyfish are not very active, watching the jellyfish feed is a soothing activity. Just be certain not to overfeed your jellyfish! This will cause your water to get polluted by the uneaten food that will rest on the bottom of the tank. Your jellyfish will be unable to eat this, as it is not in the water current. If you have fed your jellyfish too much, simply siphon out the excess from the bottom of the tank.

But Is Dry Food Enough

Look familiar? You might remember these eggs as ‘Sea Monkey’ eggs!

Ah, the question I’ve been waiting for! Is the freeze-dried zooplankton enough? Simply put, no. Not on its own. It does need supplementing. We have thought over this, and has taken action to provide the proper supplementation to our dry food. The supplement? Brine shrimp.

The reason that we don’t just use frozen brine shrimp is because it simply isn’t as nutritious as live. In addition, though frozen brine shrimp is readily available, it’s often the wrong size for jellyfish. Jellyfish have small mouths, and the frozen brine shrimp on the market is often too large for the jellyfish to eat. What jellyfish need are freshly hatched brine shrimp.

To hatch brine shrimp is simple. To make it simpler, we provide the Brine Shrimp Hatchery Disk, which makes hatching brine shrimp easier than ever before. Simply put diluted salt water into the disk, a spoon full of eggs, and place the hatchery disk in a warm area. The brine shrimp will hatch within the next 12-24 hours, and you will have live, freshly hatched brine shrimp ready to feed your jellyfish with!

Expect to see a cloud like this when feeding brine shrimp. It’s really a sigh to behold!

The process of feeding the brine shrimp is much the same as with feeding live food. Using a baster, transfer the amount you need from a container of tank water and brine shrimp, and slowly push the brine shrimp into the current.

Feeding live food to your jellyfish helps them live longer, look better, and keeps them more active. In addition to being much healthier for your jellyfish, it also means there’s less mess to clean up, as the brine shrimp stay in the current longer for the jellyfish to catch them. For these reasons, at Jellyfish Aquarium, we like to feed freshly hatched brine shrimp more often than dried food.

Of course, this does not discount the dried food. Often, it’s best to use a bit of both to give your jellyfish the best lives possible. And not matter what food you use, your jellyfish still poop. So you will still need to do weekly maintenance on your aquarium.

Bon Appetit

Today we covered what jellyfish eat in the wild, what we feed them in captivity, how to feed them and how often to feed them. It’s a food for thought when purchasing your jellyfish supplies, but maybe you’re still looking for dessert? In which case, below is linked a variety of sources on what jellyfish eat, and how they eat. If you’re interested in learning more about brine shrimp, feel free to reach out an email us through our contact page, or wait for us to post a blog all about brine shrimp, and how to make your very own brine shrimp hatchery!

Best of luck with your jellyfish, and don’t forget to check in next week for more news on the Jelly Roll!

Next Blog: To Care for Jellyfish

If you want more jellyfish content, a certain topic addressed, or you saw a really cool article on jellyfish, please tell us your thoughts in the comments below!

Purchase Jellyfish Food!

Jellyfish Food:

Brine Shrimp Hatchery: 


What Jellyfish Eat-


How Jellyfish Eat-


The Nitrogen Cycle

What it Is, and Why It’s Important

What is the Nitrogen Cycle?

Well, to answer the question of how the nitrogen cycle is important, it’s important to know what the nitrogen cycle even is! The nitrogen cycle is essentially the process of breaking down waste in your aquarium using something known as ‘beneficial bacteria’.


It starts with ammonia. When waste is introduced into an aquarium, it will slowly build up.If the pH is not at 7 or above, something called ammonium will form, which is non toxic, but also not essential to the nitrogen cycle. What you want is ammonia, which is toxic to form. It sounds counter-productive, but it makes sense, as the bacteria that you want to develop only wants to eat ammonia, which is only formed at pH levels of 7 or more. This bacteria is crucial for the next stage of the nitrogen cycle to occur.

This bacteria, known as ‘nitrosomonas’, will slowly eat away at the ammonia. Soon enough, you will have a colony of nitrosomonas living in your tank. As the colony grows, and more bacteria eat and poop, they oxidize the ammonia. This oxidization process of the ammonia produces the next stage of the cycle: Nitrites!


So, you have a bunch of bacteria chowing down on ammonia, and they’re producing a waste called nitrites. This is good! However, the nitrites that the nitrosomona bacteria produced is still highly toxic, just not as toxic as the ammonia that the nitrosomonas are dealing with. You don’t want to have this nitrite in your tank. So what do you do? You wait. See, as the nitrite levels begin to rise, another form of bacteria will form. This bacteria is known as nitrobacter.

As nitrobacter forms, they will start converting the nitrates in your tank into nitrate.


Nitrates are the final products of the nitrogen cycle. These are least harmful to your jellies, but they still pose a risk if they get out of hand. You’ll want to keep a close eye on these.

So How Do You Start the Cycle? How Do You Monitor It?

Starting the Cycle

To start the nitrogen cycle in your tank, you first have to make the water for your jellyfish tank. We have a blog post on how to mix saltwater for your tank, so, you know, check it out (please). Or there’s plenty of youtube videos, wikihow articles, or just generally informative websites that can teach you how to mix water for your tank. In fact, before reading on, please go and check out a source on how to make the water. I can wait. Trust me, I have time.

You’re back? You know how to make saltwater? Good because you’re going to need it. Fill your tank with it, and introduce a source of ammonia. Now, some people would encourage you to throw a fish in your tank, but this is considered by most inhumane. Not only that, but as you (better be!) dealing with saltwater, you may notice that saltwater fish are very expensive. Not only that, but once your tank is cycled, you can’t exactly keep jellyfish and regular fish together. So, putting a fish in your tank just isn’t a viable option. So what next?

Well, you can use a method known as ‘fishless cycling’. To do this, you introduce ammonia by adding in some fish food. Just as much as you would add if you had fish in the tank. If someone is confused by what you’re doing, just tell them you have invisible fish. When you leave the food in the tank, it decomposes into ammonia. You can add some extra food (again, as much as you would use in a regular feeding) about every twelve hours.

And with that, you have started the cycle! Congratulations! But, you aren’t finished yet, as you know! You have to maintain the cycle!

Maintaining the Cycle

So, you have ammonia in your tank. Now you have to figure out how much ammonia is in your tank. How? By using a test kit! You can use a test kit from our starter kit, or you can purchase a test kit online or in your local pet store. We like to use the Seachem Marine MultiTest kit to test our tanks, but the API test strips are just fine as well. What you’re looking for is to have the ammonia levels at around 3ppm (parts per million). If you see the ammonia levels drop, add some more fish food, and try to keep the readings stable for about a week. It’s okay if the readings aren’t always at 3ppm, but that’s what you’re aiming for.
So a week has passed, and you’ve been trying your best to keep ammonia levels stable. Now, it’s time to start testing for nitrites! As soon as you get your first reading of nitrites, you’ll know the cycle has begun.

At this point, you’ll want to keep adding the fish food occasionally, but you’ll notice the levels of nitrites will steadily rise. However, after another week or so, they’ll start dropping. Now is the time to test for nitrates. I’d also take this time to celebrate, as at this point, the cycle is nearly complete! You’ll have jellyfish in no time!

But, you have to keep testing the water! Do this every day, and be patient. This process could take another week or so. However, your patience will be rewarded! Once the ammonia and nitrite levels are at 0, your cycle is complete! That said, if your nitrates are over 40ppm, you’ll want to do a partial water change to bring the levels down.

So What’s Next?

So now your tank is reading 0 ammonia, 0 nitrites, and less than 40ppm of nitrates. What’s next? You have worked hard to get your tank set up for over two weeks now. It might have even been a month by this point! But, your work has paid off.

At this point, it’s time to visit to pick up your new jelly friends!

Our Sources:


Our Kits and Packages

Jellyfish Aquarium believes that customers deserve the best quality items to maintain their jellyfish tanks. For this reason, we have created two separate packages that we consider essential for caring for your jellyfish.

The Pro Maintenance Kit includes all the equipment you need to clean your jellyfish tank.

The first package to cover is the one that is essential for cleaning your tank. This package is the ‘Pro Maintenance Kit’, which you can find on our website store under the ‘Kits’ category. This kit includes a small siphon, an acrylic-safe algae scrub pad, an acrylic-safe cleaning cloth, and something we’ve coined the ‘Jelly-Thing Tool’. All of these tools are used together to keep your tank spotless. These tools are also all available individually under our Cleaning Equipment tab, located under Equipment in the shop categories. This kit is needed to care for the tank, and maintain the water quality. Thankfully, this package is generally a one-time purchase, as you’re only purchasing tools.

The Quarterly Supply Package has everything you need to feed and care for your jellyfish friends.

The second package includes all the supplies to care for the jellyfish themselves. Our ‘Quarterly Supply Package’ for a 2 gallon tank includes 25g of dry jellyfish food, 10 gallons of jellyfish salt, 1 pack of Chemipure Blue (Nano Sized), and 100ml of Seachem Pristine for biomaitenance. There is a variant of this kit that also includes API 5in1 test strips to check how healthy your water is for your jellyfish. These kits are absolutely essential for caring for your jellyfish, from feeding them to giving them water. We strongly recommend that you purchase this kit to give your jellyfish the best life possible.

At Jellyfish Aquarium, we take care of our jellyfish to the best of our ability. We know that with these packages, you will be prepared to give your jellyfish a long and healthy life as well.

Pro Maintenance Kit:

Quarterly Supply Package:

Quarterly Supply Package with Test Strips: