This post appears originally at jellyfishaquarist.com, and is by the very talented  jelly aquarist Wyatt Patry. Wyatt cares for jellies at the Monterey Bay Aquarium, and with his considerable experience has developed a simple, inexpensive and beautiful DYI jelly tank. Not only is this a big plus for jelly fans, but efforts like this also help scientists interested in studying these animals. The most difficult part of studying jellies is often keeping them alive. Thanks to Wyatt’s continued efforts, studying and keeping jellies is growing easier by the day. Thanks Wyatt! 

Your Summer Project: DIY Jellyfish Aquarium Using the Ecopico

I was lucky enough to receive an Ecopico from Ecoxotic recently to try and figure out a way to turn it into a jellyfish tank. I’m happy to report that I’ve had several moon jellyfish  living in the tank now for over a month with minimal care. Read on to see how to build your own jellyfish aquarium…

First, the obvious, you need to get an Ecopico. There isn’t much to setup, just clamp the light on to the back of the tank. Some plastic clips support the glass lid. You can check out the basics on setting the tank as a normal fish tank here.

In addition to the tank, you will need a few supplies; an under gravel filter plate with air tube, a small air pump, a valve for airlines, some airline tubing and rigid airline tubing. All of these can be found at your local pet store.

You will want an under gravel filter that has a modular air tube so you can place it wherever you want. Some of them are fixed in place, you don’t want those. This one at PetSmart is what I used. Connect all the filter plates together and place the air tube in the middle as shown below. You may need to cut a side off one of the plates to make it fit in with the rest.

Center your gravel plate in the EcoPico, you will want the substrate to hide the plates around the edge of the tank…

Next you need to choose a substrate. I prefer these small, jellybean #1 size, glass beads from American Specialty Glass. You’ll need at least 2″ of these beads, which works out to about 7 pounds worth of glass, I ordered a 10# bag so there would be plenty just in case I needed to add more. You can of course use any other glass bead you can find, sometimes dollar stores carry these beads. You just need to use the right size bead, read here to find out why! You don’t want your jellies getting sucked down into the substrate. Go ahead and add your beads by hand, don’t just dump them in carelessly.

Now connect the rigid airline tubing to the airline and pump. Feed the line through the Ecopico LED bracket, it helps to hold it in place. I used some nice black silicone airline, as it blends in well with the LED bracket.

You should be ready to add water! For salt mixes, I use E.S.V. B-Ionic. This salt comes in  3 parts, the sodium chloride crystals, magnesium crystals and liquid trace elements. Because it comes in 3 parts like this it mixes much faster and clearer than other salt brands. Having large undissolved salt crystals in your water is not optimal for your jellyfish aquarium! You will want to mix your salt in RO/DI filtered water or distilled water, do not use tap water.

After you fill the tank be sure to smooth out the beads. You will want to allow some time to seed your tank with bacteria to drive your nitrogen cycle but it is possible to add jellyfish immediately. I added 3 small and 1 medium moon jellyfish immediately and performed water changes everyday for a week to keep ammonia levels down. Keep this in mind when setting up a small tank like this, ammonia will build up quickly and it is best to stay ahead of the game before it can become a problem for your jellyfish. A typical sign of ammonia being too high is that the oral arms will look ‘burned’ off or severely shortened, the tentacles may also be shortened or not extending. If you see this you need to start changing water. An easy way to manage your water changes is to buy a sturdy Brute trashcan and mix your salt all at once, effectively creating a saltwater reservoir, this way you aren’t mixing salt every time you want to do a water change. You can easily cup out water and then go get clean water all ready to go. If you do keep a reservoir you will need to stir it because it is possible for the water to stratify with different layers of salinity over time, if you’re using the reservoir regularly though this usually isn’t an issue.

Once the jellyfish are in the tank you are probably wondering; how much air should I bubble? It is difficult to count bubbles when they’re moving so fast, so here is a video of what your bubble rate should look like…

We are going to follow the same “rule of flow” for jellyfish with this tank as with any other; we want just enough flow to keep the jellies off the bottom and suspended, no more than that.

As for feeding, I feed live brine shrimp several times per week for this setup. I like to alternate feedings with water changes, so for example… on Monday I’ll feed some brine shrimp, Tuesday I’ll do a water change, feed again on Wednesday, Friday and Sunday with a total of 3 water changes on Tuesday, Thursday and Saturday. You can feed other products such as R.O.E. or Rotifeast by Reed Mariculture but live brine shrimp, or evenlive copepods are now available from AlgaGen, are the preferred foods for moon jellyfish.

The jellies have been flowin’ and growin’ in this Ecopico for over a month now, I am confident that you can emulate this success. I tried to leave the tank alone as much as possible, even missed a few feedings and water changes to really ‘stress test’ this DIY jellyfish aquarium. It works great! That being said, let’s talk about expectations for this setup… if you are looking to keep jellies for say around 6 months then this is a great tank for that, but if you want to attempt to keep jellyfish for over a year then you will need a more robust setup, such as the Cubic jellyfish aquarium. Keep in mind that moon jellyfish are seasonal animals with what is most likely a natural life span of about 6-12 months. Now that I’ve set this expectation, if you can get your moon jellyfish to live longer than 6 months in the Ecopico, then I want to hear from you! I’ll gladly post your tank photos here on jellyfishaquarist.com.

Enjoy…