Once a month you should carry out a 25% water change (drain off a quarter of the aquariums water volume), clean your filter and do a general clean-up of the fish tank.
There may be other times that you also need to do a water change such as; starting your new aquarium (we recommend you do more frequent, smaller water changes for the first 8 weeks), after testing the water quality (see test kit instructions manual for recommendations) or if you need to treat the water with fish medication.
Essentially, a water change is removing a percentage of the aquarium water and replacing it with fresh water. Doing this removes waste and dirt, dilutes any build-up of toxic elements and increases oxygen levels in the water – all great for aquarium life.
The video below runs you through the process of a water change to make sure you get the job done efficiently:
Doing the water change:
Start by testing your aquarium water for Ammonia, Nitrate, Nitrite and the pH level using an aquarium water test kit.
Follow the instructions on the testing kit and make sure to keep a record of your results.
By testing your water at this point, you can address any issues you may have as part of the water change and you have a record to come back to when you test in the future.
Turn off power to your aquarium including your heater if installed. This is for the safety of both you and your fish (although you may keep your filter running).
Put the gravel cleaner into the aquarium with the tube end pointing into your bucket. Start the water syphon following the gravel cleaner instructions and begin to remove water from the tank.
As the water is sucked out you can push the gravel cleaner into your substrate this will remove any waste that has settled on the bottom of the aquarium.
Do this throughout the whole aquarium but keep an eye on the water level as you only want to remove around 25% of your water.
Once you’ve removed 25% of the water you can begin maintenance on your aquarium, this might include:
Removing dead leaves
Trimming excess plant growth
Cleaning glass algae using a magnetic aquarium cleaner
Removing rocks, plastic plants and ornaments and cleaning them (do not use chemicals or cleaners for this. Scrub using a clean brush and water, if needed).
Whilst the water level is still low you can replace the filter cartridge.
Replace the cartridges using the right service packs for your filter. Some media, like sponges, may need rinsing through to clear any small blockages.
NEVER clean your filter media in tap water always use the water that you’ve removed from your aquarium (that’s why we suggest collecting it in a bucket). Cleaning in tap water will kill all the good bacteria that you’ve spent months harvesting in your filter.
Once you’ve finished all the maintenance tasks you can dispose of the old aquarium water down the drain and refill your bucket with tap water.
Before you can add this water to your aquarium you need to treat it to remove any harmful elements.
You also need to be aware of the temperature of your aquarium; if you have a tropical tank you need to heat your water to a similar temperature as the aquarium by adding a small amount of warm water. Use an aquarium thermometer to monitor this.
For a cold water tank let the water settle to room temperature.
Carefully fill your tank back up to the suggested volume (never higher than the maximum fill line of the aquarium).
Make sure you do this carefully to avoid disrupting your fish, substrate or clouding your water.
Continue testing your aquarium water regularly (at least monthly) and doing those important water changes.
Generally, water issues are invisible to us so regular testing is essential to keep your fish and aquarium healthy.
Throughout all of this, try not to disturb your fish too much. You might find they go a little pale and hide for a short time after the clean out.
Leave the lights off for a short while and return to your normal feeding routine once they are looking confident and active again.