Introduction A guide to caring for your Moon Jellyfish
This guide is built upon several years of observation and care for many moon jellyfish bought from a variety of sources. Initially this guide was intended for owners of the original Jellyfish Art desktop tank, but it has expanded into a general care guide regardless of tank type. It has been supplemented with reading material in several other books and websites. I hope my experiences can provide a starting point to reduce the difficulty for anyone else. Feedback, corrections, or general correspondance are welcome and appreciated. This guide was last updated on June 5th, 2022.
Tip:
Green colored boxes are good habits I found helpful in
ensuring my jellies stayed healthy.
Upgrade:
Blue colored boxes are tests or modifications I perform to ensure
that the aquarium and the environment is healthy.
Caution:
Yellow colored boxes are cautionary warnings about things that
are harmful to your animals.
Important:
Red colored boxes are strong warnings about things that may kill
your animals.
Environment How to determine if your water is appropriate for Moon jellyfish
Jellyfish require excellent water quality to
thrive1, it is highly
advisable to buy a saltwater testing kit (not freshwater) to test
the tank water. I haved used several brands of test kit, and I find
that API, Elos, Salifert, and Red Sea all produce good quality kits.
Two brands I recommend are Red Sea for its high quality ease of use, and API for its quality and lower cost. You should have your tank
water fall within the following ranges presented in the accompanying
table to the right.2, 3, 7
Jellyfish can survive outside these ranges but the further away from ideal, the greater the risk to the jellyfish should anything go awry. Jellyfish can technically survive in water that is up to 4.0 ppm total ammonia (NH3/NH4+) and 80.0 ppm nitrate (NO3-), but the aquarium water should be changed as soon as possible for the long term health of the jellyfish. The term total ammonia refers to both ammonia (NH3) and ammonium ions (NH4+); more information can be found on the internet explaining how the pH of your tank water determines the equilibrium balance between toxic ammonia (NH3) and less toxic ammonium (NH4+).
For comparison, an ammonia level of 4.0 ppm would kill a fish within hours. If the aquarium water climbs above 2.0 ppm total ammonia (NH3/NH4+), change the water more frequently until the bacteria in the tank catch up and reduce the ammonia to acceptable levels. For more information, read about the nitrogen cycle for marine life on the internet and read about the ammonia (NH3) -> nitrite (NO2-) -> nitrate (NO2-) transformation.
Jellyfish can survive outside these ranges but the further away from ideal, the greater the risk to the jellyfish should anything go awry. Jellyfish can technically survive in water that is up to 4.0 ppm total ammonia (NH3/NH4+) and 80.0 ppm nitrate (NO3-), but the aquarium water should be changed as soon as possible for the long term health of the jellyfish. The term total ammonia refers to both ammonia (NH3) and ammonium ions (NH4+); more information can be found on the internet explaining how the pH of your tank water determines the equilibrium balance between toxic ammonia (NH3) and less toxic ammonium (NH4+).
For comparison, an ammonia level of 4.0 ppm would kill a fish within hours. If the aquarium water climbs above 2.0 ppm total ammonia (NH3/NH4+), change the water more frequently until the bacteria in the tank catch up and reduce the ammonia to acceptable levels. For more information, read about the nitrogen cycle for marine life on the internet and read about the ammonia (NH3) -> nitrite (NO2-) -> nitrate (NO2-) transformation.
Table 1, Target Water Parameters
| Parameter | Ideal Range2, 3, 7 |
|---|---|
| pH | 8.0 - 8.3 |
| Salinity | 32 - 35 ppt |
| Ammonia (NH3) | 0.0 ppm |
| Nitrite (NO2-) | 0.0 ppm |
| Nitrate (NO3-) | 20.0 ppm or lower |
Tip:
Jellyfish are sensitive to rapid changes in salinity, temperature,
and pH.5
Try to keep their environment as stable as possible, especially
when cleaning the tank and changing their water. Let the
replacement water reach the same temperature as the tank, to air
for at least an hour, and check the salinity carefully.
Caution:
Your jellyfish can survive for many days in levels of
ammonia (NH3), and nitrate
(NO3-) that are much higher
than ideal, but the long-term health effects are believed to
include shortening tentacles, weaker pulsing, and a
flattened bell. If left in poor water for months, these conditions
will eventually lead to jellyfish
mortality.3
Test:
Swing-arm hydrometers (such as the one provided by Jellyfish Art)
are temperature sensitive.9
The one that comes with the tank is set for sample taking at
25°C or 77°F. Most house's ambient temperatures are
lower, and lower temperatures affect both the hydrometer material
density as well as the water sample density. There is also no
indication of what temperature standard is used for the markings
provided on the hydrometer. If your house temperature is making
the salinity readings difficult, buy a refractometer that
compensates for temperature. It's important to note that even
cheaper refractometers are good to use, because what is important
is consistency in water salinity, even if the absolute salinity is
off by +/- 3ppt. Double check that any refractometer you buy
displays its measurements in "ppt" and/or "specific gravity" and
not "brix", which is used in wine-making. I use a Vee Gee STX-3 as it is very sturdy and
keeps its calibration, but it is also correspondingly expensive.
The COCODE refractometer is no longer available on Amazon, but
a very cheap generic with ATC is available. I have not personally
used it, but it is likely still better than any equipment that
comes with your tank. Finally,
calibration fluid for your refractometer is essential to ensure that your measurements do
not drift over time.
Test:
If you are not confident in your testing kit, try testing your
freshly mixed saltwater at least once. This lets you see what a
0.0 ppm reading for ammonia actually looks like. It also is a
good way to ensure that your salt and water sources are free of
nitrates (NO3-) and ammonia
(NH3). Any of the major brand will work, such as
Elos, Salifert, Red Sea and API; I recommend either the Red Sea kit due to the high quality
components and ease of use, or the API kit on cost effectiveness for quality..
Product Links:
Water Maintenance Tips and tricks to safely change tank water
Water used for your jellyfish tank should preferably be steam
distilled or passed through a reverse osmosis and
deionization process; watch out for water that says reverse osmosis
but includes minerals for taste. Do not use tap water, this is to
prevent the possible introduction of chlorine (or chloramines)
that will harm your animals, and prevent the concentration
of metals or other contaminants building up in the tank due to
evaporation.
Water changes should be done as often as necessary to keep the tank parameters ideal for the jellies. This will depend on your tank; the Jellyfish Art and EON tanks both are suitable for one to two water changes a week. If you have any additional animals, you may have to change the water more often depending on their diet. Animals that eat leftover jelly food will remove chemical energy that heterotrophic bacteria would normally convert into ammonia. Although these cleaner animals also release ammonia, it will be less than if the food was left to rot. However, animals that eat algae are not removing chemical energy from the uneaten food. The algae only grows once the food has been converted into ammonia, then nitrites, then nitrates (which the algae consumes). You will need to change water in your tank more frequently if you have extra animals in the tank.
Freshly mixed saltwater is a potential hazard to your animals for two reasons. The first is any undissolved salt crystals may cause osmotic shock to moon jellies, which cannot handle salinity differences well.5 Secondly, freshly mixed seawater has not reached its oxygen/carbon dioxide equilibrium, and that also leaves the potential for either pH shock or corrosive oxidation.10 Jellyfish are mostly water, and are not well protected against this unlike other marine animals. If you have snails, you may see them secrete a brown sludge or ooze and tuck into their shells for several hours. After time passes, this ooze will harden into a film and then peel off. Airing the water out lets the saltwater reach a steady state and avoids chemical reactions that will harm the animals.
Do not be alarmed if your water is cloudy; it is likely caused by the beneficial nitrifying bacteria that break down ammonia (NH3) and nitrites (NO2-) into nitrates (NO3-). Over time, the water circulation will cause the bacteria to stick to the substrate and they will begin to multiply.8 Nitrifying bacteria reproduce relatively slowly, taking approximately 15-20 hours to double in population.8
If you have removed more bacteria than you'd like, you may purchase a bottle of Fritz-Zyme 9, Fluval Cycle (formerly Nutrafin Cycle), Instant Ocean BIO-Spira, Prodibio BioDigest or any other bacteria seeding product and add additional bacteria into your tank. A post by Jellyfish Art on their Facebook page implies that their live rock shipped to customers is simply live rock dosed with Nutrafin Cycle. After using all of the above, I think that they all do a passable job. Some may be better than others, but it will not matter in the long run.
Water changes should be done as often as necessary to keep the tank parameters ideal for the jellies. This will depend on your tank; the Jellyfish Art and EON tanks both are suitable for one to two water changes a week. If you have any additional animals, you may have to change the water more often depending on their diet. Animals that eat leftover jelly food will remove chemical energy that heterotrophic bacteria would normally convert into ammonia. Although these cleaner animals also release ammonia, it will be less than if the food was left to rot. However, animals that eat algae are not removing chemical energy from the uneaten food. The algae only grows once the food has been converted into ammonia, then nitrites, then nitrates (which the algae consumes). You will need to change water in your tank more frequently if you have extra animals in the tank.
Freshly mixed saltwater is a potential hazard to your animals for two reasons. The first is any undissolved salt crystals may cause osmotic shock to moon jellies, which cannot handle salinity differences well.5 Secondly, freshly mixed seawater has not reached its oxygen/carbon dioxide equilibrium, and that also leaves the potential for either pH shock or corrosive oxidation.10 Jellyfish are mostly water, and are not well protected against this unlike other marine animals. If you have snails, you may see them secrete a brown sludge or ooze and tuck into their shells for several hours. After time passes, this ooze will harden into a film and then peel off. Airing the water out lets the saltwater reach a steady state and avoids chemical reactions that will harm the animals.
Do not be alarmed if your water is cloudy; it is likely caused by the beneficial nitrifying bacteria that break down ammonia (NH3) and nitrites (NO2-) into nitrates (NO3-). Over time, the water circulation will cause the bacteria to stick to the substrate and they will begin to multiply.8 Nitrifying bacteria reproduce relatively slowly, taking approximately 15-20 hours to double in population.8
If you have removed more bacteria than you'd like, you may purchase a bottle of Fritz-Zyme 9, Fluval Cycle (formerly Nutrafin Cycle), Instant Ocean BIO-Spira, Prodibio BioDigest or any other bacteria seeding product and add additional bacteria into your tank. A post by Jellyfish Art on their Facebook page implies that their live rock shipped to customers is simply live rock dosed with Nutrafin Cycle. After using all of the above, I think that they all do a passable job. Some may be better than others, but it will not matter in the long run.
Caution:
Ensure that all items going into your tank are rinsed with
distilled water only, and not with tap water. If your tap water
is heavily treated, the chlorine will hinder the nitrogen cycle
in your tank.
Caution:
Do not change the water unless necessary for the first 4 weeks.
Each time you do, the nitrifying bacteria may take time to adjust.
Minimize feeding for this first month. This will allow the
nitrifying bacteria time to establish themselves without
generating an excessive amount of ammonia in the
tank.2
Caution:
Avoid changing more than half the tank water at once unless you are
careful in measuring the salt and water for the mix.
While it will reduce the concentrations of ammonia
(NH3), etc., it has a higher risk of shocking the
jellies due to a difference in salinity, pH or temperature.
In addition, any changes will delay your nitrifying bacteria
from "working" and reproducing as they
adjust.8 If you are
consistent in how you mix your saltwater, and the salinity, pH,
and temperature match the tank, this is not a danger.
Important:
Do not adjust your salinity by putting salt crystals or
concentrated salt water into your tank. This can kill the
animals.
Important:
Although Jellyfish Art claims their cleaner snails will eat
uneaten food, all the snails I have received do not. The picture
and description on their website is of Nassarius Vibex,
but the snails I received were Cerithum, which eats only
algae.
Tip:
Mix your salt water a day in advance and let it air out or use
a powerhead pump in a bucket. This allows the water to reach its
carbon dioxide, oxygen, and pH
equillibriums.10
Try to have your replacement water match the salinity, pH, and
temperature of the tank before doing a water change to minimize
stress on your animals.
Tip:
When mixing your salt water, it is a good habit to add the salt to
the total volume of water you desire; not pour water onto your
salt.11 This will prevent
the initial small amount of water having a large amount of salt
dissolved in it, combined with a high pH, thus causing
precipitation of
minerals11 which some may find
unsightly. This precipitate is harmless with regards to jellyfish,
do not be alarmed if you see it in your tank or mixing containers.
Tip:
Calcium and alkalinity are present in natural seawater, but are not
necessary for a jellyfish to survive (i.e. jellyfish have no
shells or skeletal structure). However, alkalinity in seawater does
raise the pH, making it much easier for owners to reach ideal pH.
The salt mixes with alkalinity and calcium are slightly more
expensive, but it is much easier and convenient to reach an ideal
pH.
Upgrade:
Instant Ocean Reef Crystals is a commonly used brand by many reef and fish
only aquarium keepers. It dissolves evenly, quickly, and has a
reliable manufacturing process. Also, it comes in several
convenient sizes; I typically buy a reef salt mix that mixes either
160 gallons or 200 gallons. The 160 gallon mix comes in a handy
5 gallon bucket, while the 200 gallon mix is more cost effective.
If you are unsure of how long you'll keep your jellyfish, it comes
in smaller sizes to mix 25 and 50 gallons respectively.
Upgrade:
You can buy Fritz-Zyme 9, Instant Ocean BIO-Spira and other
nitrifying bacteria supplements on Amazon. I have used them all
and they all work; I personally think Prodibio BioDigest is the
most convenient since it ships in individual glass vials, letting
you save doses for the future (each vial can keep for years), but
it is also the most expensive.
Product Links:
Feeding How to ensure your jellyfish get the necessary nutrition
In the wild, jellyfish will normally have their prey bump into
their tentacles and oral arms.1
The prey is stung by nematocysts on the thin hair like tentacles on
the edge of the bell as well as the oral
arms.1 The stung prey is
quickly dragged to the edge of the bell and the jelly's pulsing
movement tranfers the prey to the four large oral arms in
center of the bell.1, 5
As the oral arms retract, prey is moved up into the mouth and then
into the four stomachs.1, 5 It
is uncommon but not extremely rare to find mutant specimans with
five or more stomachs. This has no effect on the jellyfish's
ability to capture and digest prey.
The nematocysts are part of how the jellyfish stimulates itself into movement; feeding properly is an important part of making sure the jelly is cared for in the long-term.2
The feeding procedure is relatively simple. Gently and slowly squirt food into the tank, and away from the jellyfish. You will need to adjust the food dosage so that enough is caught by the jelly, as well as siphoning out uneaten food to avoid fouling the tank. Feed your jellies once per day. Jellies can miss feeding for many days without dying, but make sure to feed them twice per day for every day of missed feeding. If you have the time, you may also divide the day's food into multiple feedings per day.
The jelly should retract its oral arms and slowly (over the next 5-30 minutes) have the food travel up the oral arms and into the four stomachs in the bell.
If the food is bunching up at the mouth but not traveling into the four stomachs, check the pH of your tank. A pH that is on the high side of the acceptable range (e.g. 8.4) may cause the cilia that move the food into the stomachs to not function as effectively.
If that does not solve the issue, check your food source. You may have rotten food or inappropriate food material. Try a different source; many retailers that sell jellies also sell their own food packages. See to the right for some sources.
The nematocysts are part of how the jellyfish stimulates itself into movement; feeding properly is an important part of making sure the jelly is cared for in the long-term.2
The feeding procedure is relatively simple. Gently and slowly squirt food into the tank, and away from the jellyfish. You will need to adjust the food dosage so that enough is caught by the jelly, as well as siphoning out uneaten food to avoid fouling the tank. Feed your jellies once per day. Jellies can miss feeding for many days without dying, but make sure to feed them twice per day for every day of missed feeding. If you have the time, you may also divide the day's food into multiple feedings per day.
The jelly should retract its oral arms and slowly (over the next 5-30 minutes) have the food travel up the oral arms and into the four stomachs in the bell.
If the food is bunching up at the mouth but not traveling into the four stomachs, check the pH of your tank. A pH that is on the high side of the acceptable range (e.g. 8.4) may cause the cilia that move the food into the stomachs to not function as effectively.
If that does not solve the issue, check your food source. You may have rotten food or inappropriate food material. Try a different source; many retailers that sell jellies also sell their own food packages. See to the right for some sources.
Caution:
Do not squirt food directly at the jellyfish, despite what the
instructions from Jellyfish Art state. In the long-term, this
will disrupt the natural interaction of how its nematocyst
stinging cells help stimulate the jelly's
swimming.2
Tip:
Ensure that the container used to mix the food is clean. Dirty
containers can establish large bacteria colonies that transfer into
your tank, possibly harming your jelly. With some bad luck a
saltwater strain will cultivate in the container and eat holes in
the jelly.2 In extreme cases,
the jelly may totally disintegrate within 48
hours.3
Tip:
While not strictly necessary, hatching live baby brine shrimp is
a helpful way to ensure your jelly gets proper nutrition. Live
food is an easier way to ensure the jelly gets its food without
excessive cleanup. However, the process is labor intensive,
so it is matter of tradeoff, whether you prefer cleaning or
breeding. See the
baby brine shrimp enrichment guide
on this site.
Upgrade:
If your pH is too high, you may add a small ¼ cup of
marine sand
into your tank to lower the pH. Any sand acceptable
for reef keeping will do, avoid sands that are not intended for
aquatic purposes as they have a different chemical composition
and will not lower the pH, in addition to introducing unwanted
elements into your tank (e.g. metals, etc.). I bought this sand,
but there are many others that are also appropriate (and come
in smaller quantities).
If you are not already using a reef salt with calcium and alkalinity present, consider switching (see above). The minerals present in reef salt are naturally present in seawater and are useful at moderating the pH from becoming too high or low.
If you are not already using a reef salt with calcium and alkalinity present, consider switching (see above). The minerals present in reef salt are naturally present in seawater and are useful at moderating the pH from becoming too high or low.
Upgrade:
Frozen Artemia nauplii have the advantage of being very similar to
what jellyfish eat in the wild. The disadvantage is that the dead
nauplii will eventually sink rather than circulate in the tank,
requiring clean up and water changes. While costly,
Moonjellyfish.com does grow its own jellies in its labs, so the
food is of known quality.
250g of frozen Artemia from Moonjellyfish.com
250g of frozen Artemia from Moonjellyfish.com
Upgrade:
Manufactured foods are created by drying and crushing various
plankton and animal tissue and then reforming into small pellets
of various sizes. Reputable aquaculturists have successfully
raised jellies on these foods. Manufactured foods are also much
cheaper. Like frozen foods, frequent water changes are a must with
these foods, as much will disintegrate and rot rather than be
eaten.
2oz of Golden Pearls from Brine Shrimp Direct
2oz of Golden Pearls from Brine Shrimp Direct
Product Links:
Health and Exercise How to prevent your delicate jellyfish from coming to harm
Jellyfish require a gentle current to maintain their shape and their
health.1
Your jellyfish should have enough current to be lifted off the
bottom of the tank if they sink. Owners of the original Jellyfish
Art tank (without the substrate flap) will want to reduce the
current enough that the jellies will not become scratched from
brushing against the substrate. The owners of the
EON and
Cubic tanks do not need to worry about this.
Accordingly, jellyfish are delicate; being sucked through the substrate, air channel, or filter box (exactly which depending on what tank is owned) is harmful. If you own an original Jellyfish Art tank, you can avoid this problem by ensuring there are no pieces of live rock or substrate are blocking the air channel at the base of the tank, causing a strong point of suction. If your jellyfish are being sucked into the air channel from the top, this is caused by the air channel being completely blocked at the bottom of the tank. Gently clear out the substrate and live rock gravel at the bottom, taking care not to touch the jellies. If you prefer, you can gently scoop them into a clean container for safekeeping while you perform this maintenance.
If harm does come to your jellyfish, do not panic. While they are easy to damage, jellyfish are difficult to kill. With care, your jellyfish can make an incredible recovery.2 Holes and large tears in the bell are recoverable so long as your jellyfish has not reached advanced age.4 Even if your jellyfish cannot eat or swim, it can still heal. Jellyfish can survive weeks without food, they will shrink and use up their bell mass to heal. Sadly, damage on older jellyfish (i.e. larger jellies) will cause jellies to scrunch up as they heal, permanently disfiguring the jellyfish, although it can still eat and survive.
The first things a jellyfish regenerates are to repair its bell and regrow its oral arms. As a last resort, you can move it into any clean glassware and dump in a dose of nitrifying bacteria (Fritz-Zyme 9, Fluval Cycle, etc.) to help eliminate ammonia. I personally do not recommend feeding them unless you are willing to completely change out the water in the dish and reacclimate them every time (or precisely measure your water and salt to ensure identical salinity every time). A badly damaged jelly typically cannot eat anyways, and the cramped environment will generate ammonia to a harmful level quickly. Although this approach has tradeoffs, I still recommend it. Your jelly will lack a current to help it keep shape (increasing risk of eversion) but your jellyfish will avoid further damage if it has trouble swimming due to damage.
Accordingly, jellyfish are delicate; being sucked through the substrate, air channel, or filter box (exactly which depending on what tank is owned) is harmful. If you own an original Jellyfish Art tank, you can avoid this problem by ensuring there are no pieces of live rock or substrate are blocking the air channel at the base of the tank, causing a strong point of suction. If your jellyfish are being sucked into the air channel from the top, this is caused by the air channel being completely blocked at the bottom of the tank. Gently clear out the substrate and live rock gravel at the bottom, taking care not to touch the jellies. If you prefer, you can gently scoop them into a clean container for safekeeping while you perform this maintenance.
If harm does come to your jellyfish, do not panic. While they are easy to damage, jellyfish are difficult to kill. With care, your jellyfish can make an incredible recovery.2 Holes and large tears in the bell are recoverable so long as your jellyfish has not reached advanced age.4 Even if your jellyfish cannot eat or swim, it can still heal. Jellyfish can survive weeks without food, they will shrink and use up their bell mass to heal. Sadly, damage on older jellyfish (i.e. larger jellies) will cause jellies to scrunch up as they heal, permanently disfiguring the jellyfish, although it can still eat and survive.
The first things a jellyfish regenerates are to repair its bell and regrow its oral arms. As a last resort, you can move it into any clean glassware and dump in a dose of nitrifying bacteria (Fritz-Zyme 9, Fluval Cycle, etc.) to help eliminate ammonia. I personally do not recommend feeding them unless you are willing to completely change out the water in the dish and reacclimate them every time (or precisely measure your water and salt to ensure identical salinity every time). A badly damaged jelly typically cannot eat anyways, and the cramped environment will generate ammonia to a harmful level quickly. Although this approach has tradeoffs, I still recommend it. Your jelly will lack a current to help it keep shape (increasing risk of eversion) but your jellyfish will avoid further damage if it has trouble swimming due to damage.
Jellyfish that are stuck in the substrate for several hours (e.g.
overnight) will flatten or stretch out and have difficulty moving
for around a day while they recover. A jelly stuck in the substrate
for a shorter amount of time may take only minutes before it begins
to swim normally.
If your jellyfish is beginning to flip inside out (e.g. jellyfish eversion syndrome), there are several potential causes:1, 3
If your jellyfish is a brownish color, it means the jellyfish is of advanced age and is approaching the end of its natural lifespan.1
If your jellyfish is beginning to flip inside out (e.g. jellyfish eversion syndrome), there are several potential causes:1, 3
- Dramatic salinity change
- Dramatic temperature change
- Poor water quality (ammonia, nitrites, nitrates)
- Lack of proper nutrition (diet is lacking nutrients, or food not getting into stomachs)
If your jellyfish is a brownish color, it means the jellyfish is of advanced age and is approaching the end of its natural lifespan.1
Tip:
Owners of a Jellyfish Art tank can use the following steps to
rescue a jelly from the substrate without harm:
- Turn off your air pump to avoid having the jellyfish sucked through the air channel while you rescue them.
- Gently swirl your feeding pipette three times in a horizontal circle above the jellyfish to create a vortex current that will lift the jellyfish up out of the substrate. Go slowly, and be patient, it will take several seconds before the vortex occurs. If nothing happens, try again slightly faster. (Via Brian Rogers)
- If that does not work, try gently squirting water into the substrate next to the jellyfish to lift it up. Again, be gentle, your jellyfish may be "glued" to some rock, and being gentle will save its oral arms from being torn off by the force the water.
- If that does not work, you may have to stick your hand into the tank and gently remove some pieces of substrate before trying again. Try not touch the jellyfish directly with your hands or the feeding pipette
Caution:
The greatest danger to your jelly is still poor water quality;
without excellent water quality your jellyfish will have greater
difficulty healing, and may permanently evert. Jelly eversion can
become permanent and kill your jelly by preventing it from feeding.
Upgrade:
If you did not receive an air valve with your jelly order,
you can adjust your air pump by tying a loose knot in the air hose
leading into the tank.
Alternatively, you can buy a 2-way air valve from any fish store
and cut your air hose in half and install the valve to connect
the two pieces (verify width first!). Give the tank at least
10 minutes to allow the full current change to occur before
making further adjustments.1
Tip:
If your jelly gets stuck in the substrate, turn your water pump
off for a short while until you are sure it has regained the
ability to swim. Depending on how long the jelly was stuck, it
will take several minutes to a day for it to regain its shape and
swim normally. Your pump can remain off for up to 4 hours before
it will slowly drip water from the escape valve.
Tip:
Gently swirl the water with the feeding pipette to give the jelly
some current while your air pump is off.
Upgrade:
If you own an original Jellyfish Art desktop tank (without a
substrate flap), it is highly recommended you
replace the substrate provided with something smaller but porous.
I have been using Carib Sea coarse calcium reactor media, but
there are many other options available.
Product Links:
Retailers Where you can buy jellyfish tanks and animals
Tanks |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Jellyfish Art
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Moon Jellyfish
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Cubic Aquarium
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Jellyfish Art's kriesel desktop tank uses a covered air
channel to generate the laminar flow that keeps the jellyfish
suspended. A light-weight porous substrate covers the bottom
of the air channel, preventing the jellyfish from being sucked
into the air channel while also acting as a biological filter,
housing the nitrifying bacteria.
Every tank comes with everything needed to get up and running, and even includes accessories for total beginners (a feeding pipette, and a swing-arm hydrometer). Deluxe editions of the tank include vouchers for live animals, as well as additional equipment, such as a cleaning magnet, water testing kit, bacteria seeding supplment, and aquarium salt. I have not owned or tested the Nano 3 desktop tank released by JellyfishArt. |
The EON jellyfish tank is a miniaturized version of
several larger tanks developed by Moon Jellyfish, the newly
established retail branch of Sunset Marine Labs. With 20
years of experience, Sunset Marine Labs has supplied
jellies and tanks to aquariums, restaurants, and homes
throughout the world. The tank generates its gyre flow
through two spray bars in the tank that generate a circular
flow keeping the jellies suspended in the tank.
The tank has an integrated filtration system that includes mechanical (a gauze filter), biological (media with nitrifying bacteria), and chemical filtration (activated carbon bags). In addition, the EON tank comes with three 2" jellyfish and 250g of food with the purchase of a jelly. I have not owned or tested the newer EON 2tube tank released by Moon JellyFish. |
Cubic Aquarium released the Orbit 20, a new kreisel desktop
tank in May 2014. While similar in appearance to the Jellyfish
Art tank, the Cubic Orbit 20 has a few features above the
Jellyfish Art tank at a slightly higher price. Notably, these
include a mechanical filtration feature, and no substrate
(which makes cleaning easier). While costing slightly over
$100 compared to the Jellyfish Art tank, the added
convenience in cleaning and higher build quality can be
worth it.
Cubic Aquariums also makes the Pulse 80 and Pulse 280 jellyfish aquariums, which are approximately 20 and 70 gallons each. Distribution of all three of these tanks changes rapidly as the Cubic Aquariums is European and is still building its relationships with US retailers. Check with the Cubic Aquariums website for links and references for finding one. |
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Pros:
Cons:
Bottom line:
The original Jellyfish Art desktop tank requires care and
effort to maintain water quality, but is the most affordable
tank. It is suited both towards experienced reefers who
already have an established tank they can exchange tank
water with, or beginners who have the time and energy to
change the water. It is also vital that the substrate be
replaced with something smaller but still porous (such as
CaribSea coarse calcium reactor media), and the current be
adjusted down appropriately.
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Pros:
Cons:
Bototm line:
The EON Jellyfish System is an excellent overall system
that has a well thought out design that reflects the
company's long history and experience with moon jellies.
Combined with the company's excellent customer support, the
tank is a great product for anyone who is interested in
having a unique and amazing household decoration/pet.
Although more expensive than other options, the tank will
give a great experience provided it is cared for properly
and the directions followed.
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Pros:
Cons:
Bottom line:
The Orbit 20 is a great tank for those who want less
maintainence but don't want to buy one of the more expensive
and larger tanks. The Orbit 20 is also good for owners
who are not yet ready to invest in more expensive tanks,
but want a quality product.
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Jellyfish Suppliers | ||
|---|---|---|
| Company | Sizes Available | Comments |
| Moon Jellyfish / Sunset Marine Labs | Small (1"), Medium (2"), Large (3") | Sunset Marine Labs has over 20 years of exprience captive breeding moon jellies down in the Los Angeles area. The owner, Nancy Sowinski, has supplied jellies to aquariums, and commercial establishments world-wide. This experience allows Sunset Marine Labs to give exact directions on how to care for them. In addition to the standard arrive alive guarantee, the company has (for now) an unofficial policy of shipping one extra animal in case something dies in transit. Although it is always possible to receive a damaged animal due to the shock of shipping, I have had a full recovery every time. |
| Pet Jellyfish | Small (2.5cm or 1") | Pet Jellyfish is one of the only UK suppliers of moon jellies, making them a valuable supplier for any European owners of jellyfish tanks. In addition, they sell various other species of jellyfish (blubber, sea nettle, etc.). |
| Jellyfish Art | Small (1.5"), Medium (2"), Large (3") | Jellyfish Art is a 6 year old company that was originally founded in San Francisco. After five years, the company was sold and relocated to Florida. Initially their specimens were wild caught, which led to issues with temperature acclimation and care. My initial purchase included at least two different species of moon jelly. They are currently working on a captive breeding program, but for now are acquiring their jellies from others. Jellies bought from Jellyfish Art are generally "wild cards", size may differ from advertised, and it is unknown what their true origin is and whether they are suited for the warmer household temperatures. |
| PB'N'Jellies | Out of business | PB'N'Jellies was founded by Wyatt Patry, a former senior aquarist at the Monterey Bay Aquarium responsible for the jellyfish exhibits. Wyatt Patry made a breakthrough at breeding Crown jellyfish in captivity. PB'N'Jellies was Wyatt's business selling moon jellies, in addition to an aquarist blog that he maintains. Unfortunately, the company has closed down as of 2017, although Wyatt is still at the Monterey Bay Aquarium. |
References Additional information and where I found it
- How to Keep Jellyfish in Aquariums: An Introductory Guide for Maintaining Healthy Jellies by Chad L Widmer
Chad was the head curator of the jellyfish exhibit at the Monterey Bay Aquarium and his book is intended to help owners raise and breed their own jellyfish. Includes a few useful practical tips on what to do and what not to do, as well as a troubleshooting guide. - Nancy Sowinski
Nancy is the owner of Sunset Marine Labs, and their retail division Moon Jellyfish. With 20 years of experience, she has provided moon jellyfish to a variety of aquariums, restaurants, and clubs world wide. - Cubic Aquarium Forums
This European company has a resident jellyfish expert dubbed Dr. T who also has contacts at a Japanese university. Their forums are full of detailed information and advice on keeping jellyfish. - PB'N'Jellies
Wyatt Patry is a senior aquarist at the Monteray Bay Aquarium, and was responsible for the breakthrough that allowed Crown jellies to be bred in captivity. He owns PB'N'Jellies, a Moon jelly supply site. - Tank Raised Moon Jellyfish by Jim Stime, Jr.
This article is written by Jim Stime, the designer of the Jelliquarium, an early home aquarium for jellyfish. The article contains a great detailed overview of what raising a large number of Moon jellyfish is like. - Aurelia Aurita
Wikipedia article on Aurelia aurita, also commonly known as the Moon jellyfish. - Sunset Marine Labs Video: Acclimating Your Jellyfish Properly
This video by Moonjellyfish.com (the retail arm of Sunset Marine Labs) shows how to acclimate their jellyfish. It includes information about what water parameters the jellyfish should have. - Nitrifying Bacteria Facts
Bio-Con Labs keeps a detailed explanation of how nitrifying bacteria function. Some of the information within is specific to a particular brand of cultured bacteria from Fritz-Zyme 9 by Fritz Aquatics. - Chemistry and the Aquarium: Specific Gravity: Oh How Complicated!
This article by Randy Holmes-Farley gives an excellent and lengthy explanation of the relationship between salinity, specific gravity, and temperature, as well as some tips on how to gauge the accuracy and precision of your hydrometer. - Low pH: Cause and Cures
This article by Randy Holmes-Farley gives an overview of pH in saltwater aquariums as well as how to diagnose and treat problems that cause out of range pH values. - What is that precipitate in my reef aquarium?
This article by Randy Holmes-Farley explains what the precipitate in aquariums commonly is and how it forms.
Contact Information How to contact the author(s)
Jonathan Hsu
I was introduced to jellyfish by the cover of Wired magazine in late 2011, explaining how a company called Jellyfish Art would make keeping a jellyfish in the home as easy as taking care of a goldfish. This was, of course, patently false, but that didn't stop me from trying. After having fun doing a year of experimentation and research, I wrote this web-site to share what I found. I have started a coral reef tank, which I blog about, updating it with news about long-term coral health, new animals, or new tools and techniques to take care of the animals.