Establishing / Cycling A New Aquarium

Many new aquarists do not recognize the importance of the nitrogen cycle and its roll in the establishment of a healthy environment in a new aquarium. This is not a process that is exclusive to jellyfish aquariums. ALL types of aquariums will go through a cycling process when newly set-up and stocked.

Fully cycling a new aquarium normally takes a couple of weeks to a month (sometimes longer).

‘Cycling’ a new aquarium, is essentially the establishment of populations of different types of beneficial bacteria in the filter media. Beneficial bacteria converts decomposing organic matter (animal waste and uneaten food) firstly, to ammonia. Ammonia is quite toxic to most forms of life including jellyfish and can cause harm quite quickly. Then another type of beneficial bacteria feed on the ammonia (yuck) and produce nitrites. Nitrites are a little less toxic than ammonia but, left unchecked, can do damage to your jellyfish as well. Then, yet another group of beneficial bacteria utilize the nitrites and produce nitrate. Nitrate is the final stage of the nitrogen cycle and is the least toxic substance in the chain. Although, nitrate in high enough concentrations will also harm your jellies. Nothing converts nitrate to anything. Removing nitrate and diluting the remainder is part of the reason we do regular, partial water-changes.

During the initial cycling process, you are trying to establish a stable environment in your aquarium. Although you want to do partial water-changes to dilute/minimize the build-up of toxic substances in the aquarium, each time you do, you destabilize the environment some. So… do partial water-changes as dictated by the aquarium’s water chemistry, but don’t do them unnecessarily for the first few weeks.


Navigating The Nitrogen Cycle

Thankfully there are test kits available to test for ammonia, nitrite, and nitrate. Testing for them regularly in the beginnings of your aquarium will give you a good idea where you are in the establishment of the aquarium’s ‘cycle’. You will see some ammonia first, then nitrite will rise as ammonia falls. then nitrate will start to build-up as nitrite falls. You ultimately want to have both ammonia and nitrite pretty close to 0.0ppm. Nitrates will normally be a little bit higher. Up to about 2oppm is alright. However, lower is better. Under 5 is ideal.

Yes, we know you’re keen to get going with your new jellyfish aquarium. However, having patience and starting out slowly, you will have an easier time managing the establishment of the nitrogen cycle in your new aquarium. In a small aquarium, we’d recommend starting out with one or two small jellyfish (you can add more later) and feed it sparingly for a couple weeks, while first starting up. If you over feed or add too many jellies at the beginning, you will almost inevitably end up dealing with a toxic ammonia level spike and unhealthy jellyfish or worse. 🙁

Utilizing additives like SeaChem’s Pristine and Stability will help with the cycle but they can’t do it all, immediately as a lot of people would like to think. They simply help.

Establishing a new aquarium takes time and there is no avoiding it. You’ll need to be vigilant with the water chemistry, aquarium cleaning and conservative with the feeding.

  • Start a new aquarium slowly.
  • Keeping a jellyfish aquarium clean is important. However, it is especially important in the initial stages.
  • In a small aquarium, we would also recommend the bowl feeding method to minimize waste in the main aquarium.