By now we all should know that the true key to keeping your jellies happy and healthy is maintaining stability in your tank. Stability is achieved after fully cycling your tank for 4-6 weeks. Once cycled, water changes are a good weekly maintenance practice because pH will gradually decrease and harmful chemicals like phosphates and nitrates can build up naturally over time, even in healthy systems. Beneficial bacteria and carbon filters in your filter box take care of a good portion of keeping your tank stable, but it’s important for you to assist in maintaining the water quality by performing water changes on a weekly basis. Be aware though, changing water is not a fix-all and when done in excess can actually harmful.
You should NEVER change more than 20% of your tank’s water volume at one time… here is why:
The ammonia level will spike after a large water change due to the beneficial bacteria dying off. This can leave you with hurt and shredded jellies. The bacteria die off because they are marine organisms, too, and when you change a large portion of their aquatic environment with that big water change, they get shocked and die. Therefore, no bacteria = ammonia spike = shredded jellies.
We recommend you change only 10% – 20% of your water once a week—no more!
It’s also good to check the parameters of your new water so you are aware of exactly what you are adding to your tank.
The point we’re making here is that water changes, although helpful, can be harmful if done in excess… like most things! 🙂
Relocating? Need some help figuring out how & when to move the jellyfish?
First, there’s a couple things to keep in mind.
Time is of the essence. As you know, your jellies need a constant current of water, so it’s not good to keep them out of their tank for more than a day. For the same reason, it’s crucial that your tank has access to electricity to keep the pump running, so you can’t leave it in your new place before the utilities are sorted out. This process needs to happen as quickly as possible to ensure the safety of your jellies, so it’s probably a good idea to save the jellyfish tank for the last day of your move.
Your filter media needs to remain submerged and in the dark the entire time. You spent a whole month cycling your tank’s bacteria, but it only takes a couple hours to kill them off again if you let your filter media dry out or expose it to sunlight for too long. Make sure you have something to accommodate your bio balls and carbon filters, for example a large, sealable ziploc bag or watertight tupperware container, and something to keep them shaded, like a drawstring bag or even just a towel to wrap them in.
Once you set the tank up, it’s hard to move. Make sure you already have the location picked out for your tank in the new house so you only have to set it up once. You may want to review this guide to choose the right place for your tank.
And here’s a list of the supplies you’ll need:
Buckets or tubs, one or two big enough to hold the water in your tank, plus another bucket for a few gallons of extra new saltwater
2-3 gallons of newly mixed/purchased saltwater to add to your system while you’re setting it back up
Large trash bags to line the bucket(s)
Zip ties to cinch the trash bags closed so the water doesn’t spill
Large ziploc bag or tupperware to store your bio filter media
Towels to keep you from ruining your new or old floors
Small cup for transferring jellies in and out of your tank
Level to make sure your tank is level in your new home
Alright, you’ve gathered your supplies, now you’re ready for the breakdown.
Step 1: Prepare the jellyfish transition container. Line a bucket or plastic tub with a trash bag, and begin to fill the bag with a few gallons of water from your tank.
Step 2: Transfer your jellies out of the tank. Unplug your tank, and gently move the jellies from your tank to your bucket using a small cup.
Step 3: Take the filter media out of the tank. Take the bio balls and carbon filters (and micron pad if you have one) out of your filter box and place them in a large ziploc bag or tupperware container. Fill the container with tank water and seal it for transportation, then wrap it in a towel or put it in a drawstring bag to keep it out of the sunlight.
Step 4: Get the rest of the water out of your tank. Fill the jellyfish bucket the rest of the way up with water, then fill another bag-lined bucket with the remaining water until your tank is empty. Now cinch your bags closed with zip ties, making sure to get ALL the air out of the bags. This way they don’t slosh around or spill in your vehicle, and your jellies won’t be harmed by air bubbles.
Step 5: Dry the inside of your tank. Give the interior a good wipe down with a towel to make sure it won’t get the inside of your vehicle wet. You may want to leave a towel in the display area and a towel in the sump just to soak up any extra water on the drive.
Step 6: Pack it up. Keep the drip tray, soffet, and lid separate from the tank so they don’t rattle around and scratch the acrylic. You may want to wrap the tank in a moving blanket to prevent scratching or other damage.
Now you’re at the new place, so it’s time to set it all back up.
Step 1: Place your tank in its new spot. Make sure it’s level before you add water, but keep in mind it may shift with the added weight of the water. If it’s not level, wedge a shim underneath it in the right places until it is. Keeping your tank level is essential.
Step 2: Add water and filter media to the tank. Take the water out of your no-jelly bucket and put it back in the tank, then keep filling it as close to the top as you can while keeping at least a couple gallons of water in the jelly bucket. Add your filter media back to the filter box, preferably using a clean mechanical filter to catch any gunk that may come out of your spray bars when you turn the pump on. Now fill the remainder of the tank with the few gallons of new saltwater you brought, keeping an eye on the sump level so as not to cause an overflow.
Step 3: Turn the pump on and wait. Now your tank is ready to be up and running again, so plug the pump back in and let the water cycle through for at least an hour before you add your jellies back. There will probably be some loose gunk from the plumbing or the biological filters floating in the system, which you can simply allow the mechanical filters to catch over time, or remove yourself with a turkey baster.
Step 4: “Burp” the air out of your tubing. As you add water back, air bubbles will start to form in your tubing and in your spray bars, which can harm your jellies if they make their way into the display area of your tank later. Give your tubing a gentle shake to loosen some bubbles, then give it a gentle squeeze to help push the bubbles out. Now move your finger under the top spray bar and push the bubbles out from underneath, and repeat the process until they’re gone.
Step 4: Acclimate your jellies. Even though your tank has mostly the same water as before, the new salt water you added may create a slight change in water temperature and/or chemistry that could potentially harm your jellies if you just dump them straight in. So just to be safe, perform 3-4 small water changes [roughly a cup (8oz)] over the course of half an hour once the water in your tank starts to clear up. Then you can gently add them back to your tank one by one with the cup you used earlier.
Step 5: Welcome your jellies to their new home! Sharing cake and balloons with loved ones is encouraged, but not necessary.
Low pH can have adverse effects on moon jellyfish over time, especially when it drops below 7.6. This problem is common in aquariums with filtration systems that don’t allow for adequate aeration or disturbance of water.
The optimal pH for moon jellyfish is 8.0-8.2. As pH lowers below this range, the water becomes more acidic and harbors excess carbon dioxide (CO₂). If prolonged, the lower-than-optimal pH can cause pitting in the bell, eversion, and bell shrinkage in jellies. Although moon jellyfish are commonly described as being “hardy” and “tolerant” of extreme water quality levels, too extreme can and will eventually cause them damage.
Filters that allow for splashing and rapid movement of water through them introduces oxygen to the system, keeping the pH up by steadily off-gassing that harmful CO₂. When filters are completely submerged in water, the rate at which the water is moving through them is little to none and can negatively affect both the water quality of your aquarium and the beneficial bacteria that you’ve worked so hard to grow during cycling. If the water isn’t moving through the filters, then the filters are doing nothing to clean the water. Adequate and efficient water flow through the filters is necessary for both the water quality and beneficial bacteria to stay in tip-top shape.
Luckily, this is an easy fix!
There’s all kinds of water conditioners, additives, and buffers on the market today that are specifically made to raise pH… for normal fish tanks, however. Since jellyfish are 96% water, they are a bit more sensitive to the chemical makeup of water than normal saltwater fish. So, adding in a bunch of chemical powders and liquids, especially into a small desktop jellyfish aquarium with less than 10 gallons of volume, isn’t always the best idea and can cause more harm than good! So, don’t do it!
Instead, we recommend the following tips to help keep your pH optimal:
Adding a bubbler is an easy and worry-free fix to raise pH. Bubblers (also known as aerators) constantly introduce oxygen to the water via bubbles. Most aerators include a valve or dial to alter the rate of bubbles giving you more control, which is even better.
It’s best to place the bubbler in the filter compartment, away from the pump, and as far down to the bottom of the tank as possible. This way, the bubbles are not being sucked into the pump and have a longer path to reach the surface, releasing a bit more oxygen into the water.
Note: You do not need an air stone, if one is included. These will only create smaller, erratic bubbles that have a higher chance of getting sucked up by the pump and into the jellyfish area – which you don’t want!
Always make sure your new saltwater has a pH of 8.0-8.2. This will help raise the overall pH of your aquarium and keep it up through weekly water changes.
We experienced this problem when working with the 6 gallon Cubic Orbit 20 jellyfish aquarium, as you can see in the video below that we put together some time ago.
***At this time, we are suspending the “program” part of our Fish-less Cycling Program due to reduced staff availability. Signups will not be accepted until further notice. If you are setting up a new jellyfish aquarium, we still strongly recommend you still cycle it using the fish-less method before introducing your first jellyfish.***
Thanks for your interest in our Fish-less Cycling Program! This program was set up back in 2016 for two reasons: 1) to help new jellyfish owners have a successful start with their new aquariums, and 2) clear up misinformation floating around the internet about the cycling process and how long it takes to successfully cycle a new aquarium. Cycling a new aquarium takes time, patience, and attention to detail but it ensures your new aquarium is biologically stable and habitable for any saltwater animal; this is not jellyfish-specific issue! This blog post provides the essential information you need to know about what cycling is and how to cycle your new aquarium. At the bottom of this post (after you’ve read every bit of information and become a cycling expert, of course!), you’ll find the sign up form to participate in our Fish-less Cycling Program.
A “fish-less cycle” is the best and safest way to cycle an aquarium, as it doesn’t harm any fish or jellyfish. The goal of cycling a new tank is to establish a healthy and strong colony of beneficial bacteria in the filters to take care of waste that is created by feeding the animals (in this case, jellyfish!). The process of cycling a new aquarium is often overlooked and can create problem right from the get-go. New jellyfish owners who do not allow their tank to completely cycle before adding their first jellyfish sadly end up with unhealthy & deformed jellyfish and become confused about why they are not well. Since jellyfish are 96% water, they rely heavily on water chemistry (a.k.a. water quality) and therefore, need a biologically stable and “chemically clean” environment in order to thrive.
Cycling takes no less than 4 weeks. There is misinformation going around the Internet about how long cycling takes. Some websites claim “it only takes 10-14 days” or “two weeks.” This is wrong. The nitrogen cycle is straight forward biology and you can’t speed up biology. Even with the use of “bio-starters,” you must still cycle the aquarium and it will still take 4 weeks minimum.
Now, let’s get to what it actually means to cycle your new aquarium!
Cycling is turning a static, non-living environment (i.e. brand new tank/filters) into a biologically stable environment that’s safe for live animals.
What do we mean when we keep saying, “biologically stable environment”? Well, the filters (i.e. bioballs, rock media, etc.) of an aquarium need to have strong, healthy colonies of beneficial bacteria established within them. Beneficial bacteria = good bacteria! They take care of the waste created from daily feedings. Cycling allows these bacteria to establish themselves by multiplying and creating large colonies able to handle the waste created within your aquarium by the fish and the food being fed daily.
The Nitrogen Cycle: This is a three-step process converting ammonia (NH₃) into nitrite (NO₂) and finally into nitrate (NO₃)– all done through the bacteria. The “cycling process” is essentially the “nitrogen cycle”! All three of these compounds will be present at some point during cycling and since ammonia and nitrite are toxic to all saltwater animals (not just jellyfish), this is why cycling should be done “fish-less” and before introducing the first animals. Nitrate is a by-product of the nitrogen cycle that will always be present in your aquarium and is not toxic to moon jellyfish under 100 ppm; so, no need to worry about nitrate while cycling! It is always maintained through weekly water changes once cycling is done.
Fish-less cycling involves placing a nickel-sized (approx. ¾” x ¾”) piece of raw shrimp (add one nickel-sized shrimp piece for every 10g of water volume your aquarium can hold) into the filter box or compartment of your aquarium. The raw shrimp will begin to decompose and create ammonia to start the cycling process. At the same time, a starter bacteria culture is added to begin the colonization in the filters. After about two weeks, the ammonia level will rise to a peak (also known as “spiking”) and then start to decrease to zero. Once the ammonia is finished spiking, the nitrite level will begin to rise. After another two weeks, the ammonia will return to zero and the nitrite won’t be far behind. Once the ammonia and nitrite levels both return to zero, the aquarium is cycled!
Thermometer and hydrometer or refractometer – to test for temperature and salinity
Fish-less Cycling Program Guidelines – this is your weekly guide to see what the *expected* week-by-week changes in water quality (also a.k.a. the nitrogen cycle) for your tank [download the PDF below]
Let’s start cycling!
Once your new aquarium is set up and running with new saltwater (salinity should be 1.022-1.024 Specific Gravity or 31-33ppt), add the bacteria source and two nickel-sized pieces of shrimp at the same time.
Take your baseline water quality readings – this includes temperature, salinity, pH, ammonia, and nitrite.
Test for pH, ammonia, and nitrite every week to keep track of the fluctuations in levels that indicate where you are in the cycle. Record these on the PDF guideline water quality sheet (download below).
Once both ammonia and nitrite have returned to zero after subsequent spikes, your aquarium is ready for jellyfish! (Keep the piece of shrimp in your aquarium until the jellyfish arrive. It will continue to feed the newly established beneficial bacteria until you begin a daily feeding routine with jellyfish).
DO read this entire blog post and the Fish-less Cycling ProgramGuidelines to fully understand the cycling process and how to cycle your new jellyfish aquarium
DON’T skip any part of this blog as it contains all of the essential information you need to know about cycling!
DO use new saltwater with the following baseline water quality parameters:
Temperature = 65-78°F
Salinity = 31-33 ppt or 1.023-24 SG
pH = 8.0-8.1
DON’T add any buffers, conditioners, or additives to your aquarium water before or during the cycle – these can throw off the water quality and disrupt or inhibit the cycle from starting
DO use Instant Ocean Sea Salt mix for your saltwater as it has no buffers, conditioners, or additives [Purchase from Amazon here]
DON’T use any salt mix labeled as “reef salt,” “pH balanced,” “probiotic,” or “enriched” as these tends to have extra minerals, vitamins, and higher levels of pH specific for corals, anemones, etc. in reef tanks
DO make sure your pump is plugged in, turned on, and working properly
DON’T keep your tank near windows and/or in direct sunlight to keep algal growth at a minimum
DO use freshwater labeled only as “Distilled Water”
DON’T use freshwater jugs labeled “Spring Water,” “Purified Water,” or anything else to mix your saltwater or for topping off
DO add distilled/RO water to compensate for evaporation (evaporation causes salinity to rise; adding freshwater helps to bring it back down)
Evaporation is noticeable when the water level is lower than where it started
DON’T add distilled/RO water near the filters – this can completely wipe out your growing bacteria colonies
Only add freshwater to the main viewing area
DO record your weekly test vial readings via pictures with the color chart
DON’T use test strips as they often give unreliable readings
DO start the cycling process with a newly setup aquarium.
If your aquarium has been running with saltwater & the bio starter bacteria for longer than a week, you will need to dump the water and start over with all new saltwater & new bacteria.
DON’T perform any water or filter changes during cycling – this can disturb the growing bacteria and disrupt the cycle
DO keep an eye on the piece of shrimp in your tank – sometimes it can completely disintegrate before the cycle is over and will need to be replaced to keep the ammonia production up
DON’T freak out if your cycle isn’t exactly on track – every cycle is different and sometimes an aquarium needs an extra week to catch up
DON’T add a bubbler if you own a Cubic Orbit 20 jellyfish aquarium before or during the cycle – aeration can inhibit the cycle from starting
Things that can delay or disrupt the cycling process
Starting with a pH higher than 8.2 can inhibit the cycling process from starting by disturbing the bacteria. The pH of an aquarium will naturally drop during the cycle – which is normal! – and needs to be left alone to do its thing until the cycle is done.
Starting with salinity too high or too low can also inhibit the cycling process from starting by disturbing the bacteria. The optimal salinity range for moon jellyfish is 31-33 ppt or 1.023-24 SG, which is perfect for cycling.
If you have the Eon 10 gallon Jellyfish System, you may have been using a turkey baster to either feed your jellies or quickly pick up any detritus or uneaten food at the bottom of the tank, or both. Most turkey basters drip terribly unless you seal the bulb to the pipette. Once sealed properly the baster creates better suction and you can quickly and easily pick up any unwanted algae or uneaten food and deposit right away into the filter box–no dripping! This makes for a quick tidying of the tank without having to pull out the siphon tube and do an entire water change.
Using a 5″ piece of electrical tape you can easily solve this problem. Electrical tape comes in many lovely colors and has the unique characteristic of uniformly stretching and creating a nice watertight seal around the bulb and the pipette.
Cut a 5″ long piece of electrical tape.
Place the 5″ long piece of electrical tape half on the bulb and half on the pipette
Place your thumb on the electrical tape and hold it firmly while firmly pulling on the tape to stretch it.
Continue pulling the electrical tape tightly all the way around to create a nice seal like this!This is easily removed & repeated when you need to clean the turkey baster once a month or so.
Another common problem concerning salt levels in your jellyfish aquarium, besides inaccurate hydrometers giving a false reading, is how the saltwater is made. Undissolved salts can also give you an inaccurate reading which is a problem since jellies are very sensitive to salinity changes & high salinity levels can also impede their movement, eating and overall cellular activity. It is important to know what your salinity is and how it changes over time.
The point I need to make here is about how you make up your saltwater with distilled or RO water.
Always prepare the saltwater at least 24 hours ahead of time. Adding undissolved salts to your jellyfish aquarium will damage the jellies tissue and can cause them to be very still and not bell or pulse much…their bell can curl under and they will fully retract their tentacles and not eat because of the tentacle retraction. They will look and be sad….sad jellies. Also a dusty film of white on the interior of your tank will form, which can make the tank look cloudy.
Properly aerating saltwater involves a small submersible pump called a powerhead, and a bucket. A simple “bubble wand” or “bubbler” will not degauss and dissolve the salts completely. I know the words “aeration” and “bubbler” tend to go hand in hand, but in this case it’s just not the right tool for the job. You need more mixing power in the water which a powerhead can give you. Once you add the desired amount of salt, vigorously mix for a minute or two with your hand or 2 foot length of PVC pipe as a stir stick. After that, you can let the powerhead pump ( in this scenario a Lifegard 800 is perfect!) do the rest. See diagram above to see how to set this up in a 5 gallon bucket. It could be any size bucket as long as you position the powerhead pump at the water level allowing it to pull in air as it mixes. You want the water and air to be churning vigorously.
If you have some residual stuff still swirling around the bottom of the bucket after 24 hours don’t worry about it. Just leave it there and don’t try and mix it into the water you will be using for a water change. You can rinse that out and get rid of it before making another batch of saltwater. It’s just undissolved minerals and is totally normal.
Important Side Note!!
Never use tap water to make up your saltwater–not even if you use some sort of water conditioner that removes chlorine. There are heavy metals, pesticides and ever more increasing levels of pharmaceuticals in city tap water supplies. No sort of chemical conditioner will eliminate these things from the water. You must use distilled or RO (reverse osmosis) water. Do not use “spring water” or “mineral water” or “drinking water” — it must say “Distilled” or if you are purchasing from a water store, it must be RO or RO/DI.
I recently had the opportunity to meet and speak at length with some new local customers who came in to learn how to keep jellyfish as pets. Payam, Lauren and their little dog Ted came down to the lab to see just what is involved with keeping jellyfish and maintaining a jellyfish aquarium. It was super to spend time with them and show them the ropes! It was then that I realized that most of the questions they had are the same questions a lot of folks send my way via email. So, I will start to shoot quick blog posts every week that cover these questions– most of which are not jellyfish specific questions, but standard aquatics questions that can be answered fairly easily and quickly. And, I will certainly get to the more specific jellyfish inquiries which will help you, as a jellyfish owner, begin to recognize and identify certain issues that can arise while caring for these beautiful animals and how to correct the problem right away.
Don’t bog your jellies down with high salinity levels in your jellyfish aquarium!
The first and biggest problem I see is maintaining water quality–specifically salinity. The problem seems to be in the hydrometers that are generally purchased to measure the salinity. The plastic hydrometers that are on the market, and even the more costly refractometers need calibration. Using either one of these instruments right out of the box will yield a variety of readings which is not good when you are trying to establish the salinity level of your aquarium. Payam left with 20 gallons of my natural ocean water, salinity 33ppt, and when he got home and tested the water with his newly purchased Deep Six Hydrometer, it was reading over 40ppt!! I knew this was incorrect. Payam returned it to the store and bought another one. Same problem. Then he purchased yet another one! Finally–Getting closer! Third time’s a charm!
Now, I know from personal experience because I have 2 of them myself and each one reads differently. The trick is to calibrate it with a known water source and then simply account for the difference each time you use it. It’s no big problem to do. The third one Payam purchased was a bit closer to an actual read and we agreed that he will bring it in for me to calibrate properly soon. The point is, if you are continually having problems with your jellyfish eating, belling or pulsing, or just not thriving, you should first look to your salinity level.
Moon jellies perform better with a salinity level between 32-33ppt. Don’t worry if you go a bit below that because lower is better than higher. Just don’t alter the salinity level too much at one time but do it gradually over a few days. And, never add distilled or RO water to your filter box as it will kill your beneficial bacteria, which are a marine (saltwater) species of bacteria and are also affected by salinity & pH. Also, keep in mind: depending on your geographic location and evaporation rate, you may need to check your salinity twice a week.
Here in Los Angeles we have very dry air and experience quite a lot of evaporation. But, again, it’s hard to know that if you have an instrument that is inaccurately reading your water. Try taking your hydrometer to your local hi-end reef / fish store and see if they will calibrate it for you. What you want to know is how many points off your hydrometer is – either too high or too low– and then just account for that each time you take a salinity reading. For example, when using my plastic Deep Six hydrometer in a pinch, I know it reads 3 points too low, so I just add 3 points to whatever it is reading. When I do have a chance to test it against my pricey refractometer, it is consistent with my adjusted plastic hydrometer read.