It is recommended to change between 10% and 15% of the water weekly to ensure optimal tank performance.
Water changes can be scheduled alongside more thorough cleanings—such as cleaning the filter sponge and performing a more extended siphoning. However, large water changes are not advised, as they can disrupt the bacterial population in the biological filter, causing it to malfunction.
You must prepare the artificial saltwater 24–48 hours in advance, ensuring it matches the aquarium’s parameters.
One risk during water changes is air entering the system, forming bubbles that may damage jellyfish. To avoid this:
Make sure the water level does not drop low enough for the pump to suck in air (especially important in models like Orbit 20, O16, Aquajelly, C8).
Alternatively, turn off the pump during the change and restart it after refilling.
Medusea recommends checking the salinity and temperature of the new artificial saltwater before the water change to match them as closely as possible to tank conditions. This ensures a smoother transition for the jellyfish.
Step-by-Step Water Change
Remove the advised amount of water:
Up to 1.2 L for Aquajelly and C8
Up to 3.5 L for Orbit 20 and O16
Refill slowly, taking care not to create bubbles.
Open the valve and restart the system, if necessary.
It is essential to prevent bubbles or microbubbles during and after the process, as they are highly harmful to jellyfish.