Maintenance - Water Change
A water change is one of the simplest yet most valuable maintenance tasks you can perform. While your Living Oceans Aquarium is designed to remain biologically stable for decades, regular water changes replenish essential trace elements, export excess nutrients, and help maintain the ideal environment for your fish and corals.
We recommend replacing 25–50% of the aquarium water every 8–12 weeks. Combined with routine cleaning, this preventative maintenance helps keep your reef healthy and resilient for the long term.
Why Water Changes Matter
Unlike freshwater aquariums, a reef aquarium relies on a careful balance of minerals and trace elements that are gradually consumed by corals and other marine life. A scheduled water change restores these elements while reducing dissolved nutrients and organic waste before they become a problem. Preventative maintenance is always easier than correcting water quality issues after they occur.
Prepare Before You Start
Switch off the aquarium and protect the surrounding area with towels. If you're troubleshooting an issue or sending water for testing, collect a 50–100ml sample before disturbing the aquarium. Carefully lift and set the light aside, allowing it to hang from its cable, and remove the mesh lid.
Clean hands are equally important, wash away any soaps, lotions, or chemicals, and wear aquarium-safe gloves whenever handling equipment or working inside the tank.
Replace Your Filter Media
Every water change is the ideal time to replace the Carbon Filter Media in the top filter basket. The Phosphate Remover only needs replacing if a phosphate test confirms elevated phosphate levels.
Before installing new media, rinse each bag thoroughly under tap water to remove fine dust. The lower baskets containing the Bio Media must not be cleaned, they house the beneficial bacteria responsible for the aquarium's biological filtration. Always place the filter media basket on top.
If you notice bubbling or gurgling after reinstalling the filter basket, gently jiggle it and push it firmly against the left partition of the filter to release any trapped air.
Remove the Old Water
Using the siphon supplied in your Maintenance Kit, slowly remove 25–50% of the aquarium's water. Place the smaller bucket inside the larger bucket to act as bunding in case of overflow, and position the end of the hose at approximately half the depth of the aquarium as a safeguard.
As you siphon, vacuum any accumulated detritus, leftover food, or loose algae from the substrate. Removing this organic waste during a water change helps reduce future nutrient build-up without disturbing the biological stability of the aquarium.
Never leave the siphon or pump unattended while operating.
Mix Fresh Saltwater Correctly
Fresh saltwater should always be prepared before refilling the aquarium. Using filtered tap water, mix 300ml of salt per 10 litres of water and swirl until fully dissolved. Add water conditioner to neutralise any residual chlorine, follow the label for dosage. Check salinity with the Hydrometer, aiming for approximately 1.024 (within the green marks), and adjust temperature to around 24°C so it closely matches the aquarium. Taking a few extra minutes to match temperature and salinity minimises stress on your livestock.
Refill the Aquarium
Slowly pump the new saltwater back into the aquarium until the water reaches the overflow weir. Once power is restored, check the rear pump chamber and top it up with approximately 3 litres of additional saltwater if needed until the ATO sensor is fully submerged. Plug the ATO back in and confirm the sensor flashes then holds solid green.
Adjust the circulation nozzle so it directs flow horizontally towards the centre of the aquarium, do not angle it upward, as this causes unnecessary surface agitation, noise, and salt creep.
What to Expect Afterwards
Don't be concerned if the aquarium appears cloudy immediately after maintenance, disturbing the sand bed and water column is completely normal, and the water usually clears within a few hours. Many corals will also temporarily close after a water change and typically reopen later that day or over the following couple of days as they readjust to stable conditions.
Make Maintenance Part of Your Routine
Water changes don't need to be complicated. By completing them every 8–12 weeks, replacing your filter media, and using the included Maintenance Kit, you'll provide your reef with the conditions it needs to continue growing for years to come.
Every Living Oceans owner has access to the Living Oceans Support Hub, with detailed Assembly and Training Videos covering water changes, equipment maintenance, and ongoing reef care. If you need additional help at any stage, contact the team at support@livingoceans.com.au.
