Cleaning your fish tank consists of a few different steps. Firstly, the physical aspect of cleaning any algae or other growth on the glass or ornaments, which is done by using an ordinary sponge.

The other part is considered cleaning but also necessary maintenance. This requires removing some of the water in the tank or aquarium and replacing it with fresh tap water. This can be done by using a gravel cleaner which gets deep into the gravel and removes any excess waste but also removes water at the same time. If you don’t need to do a gravel clean, you can also remove water with a cup and bucket.

Things to consider through this process that are extremely important to note:

  • Fish do not need to be removed while you are doing this. You just need to carefully work around the Removing fish can cause them more stress.
  • You only ever want to remove 25-30% of the water at any time unless there is a major
  • You want to take care not to expose filters or heaters through the process, this can cause serious damage to If needed it is best to turn them off prior to starting.
  • When adding water back into your tank, do so slowly. This is more critical for tropical fish but still relevant for cold. Fish can stress at a change of temperature of as little as 1-2oC. Slowly add the water back in, allowing the heater to slowly bring the temperature back up to its desired
  • Don’t forget to add some water conditioner to your water. Tap water contains chlorine and other chemicals that makes it safe for us to drink, however is very harmful to our fishy friends. Water conditioner detoxifies these chemicals to make it safe. Untreated water can also affect the beneficial bacteria in the tank

How often should you clean it?

How often really depends on a couple of factors. The size of the tank plays a part, and how many fish are living in there. In general, small to medium tanks require cleaning every 1-2 weeks while larger tanks can sometimes go for 3-4 weeks. However, there are other factors that can alter this.

Important note, it pays to conduct regular water testing as sometimes you can’t physically see what needs cleaning. Water testing can be a great indicator when a water change may be needed and testing can be done at your local PETstock for free, simply take in a sample of aquarium water.

How often should you change tank water?

Again, it depends on the tank and other factors. Sometimes you can have algae growth, but your water could be healthy. In that instance you would only need to scrub off the growth and not do a water change. However, it is recommended that you still do – when cleaning off algae and other growths, particles end up floating in the water and a water change helps remove some of that waste.

What are some top tips for keeping healthy fish?

Keep it simple. A major stress factors for fish is temperature control. Keep the temperature as consistent as possible. Is the tank near a heater or air conditioner, window or door for example? Keep tanks away from things that can alter temperature.

  • Don’t overfeed your fish. Feed them smaller amounts more often. Anything left over after 5-10 minutes should be scooped out with a
  • Maintain your filter so it’s running
  • Don’t over crowd your tank. The more fish you have the more waste they’ll create, which alters water It also affects oxygen levels in the water.
  • Test your water weekly as a minimum. Know what is going on and be proactive to keep a healthy environment for your fish, rather than reactive when you see something visibly
  • Most importantly, be consistent. Have a routine that works for you. If it is fortnightly cleaning, be

What is your advice for sick fish?

Illness in fish can be from several causes, but the first thing I always suggest is check if there is something causing stress for the fish and eliminate that first. Temperatures, poor water parameters, poor filtration and over feeding can all cause stress to your fish. If you catch the problem during early stages, it is much easier to treat.

Pop in and see your local fish specialists. Take them a photo of the illness if you can’t identify it yourself. They can advise the correct type of medication to use and the steps needed before and after.


About PETstock Aquatic Specialist Kyri Pantelidis

Kyri has been PETstock’s fish specialist for more than four years. He is responsible for the care and welfare of PETstock fish while they are in store care and ensuring that when fish move on to their forever homes, customers have the necessary knowledge to care for them. Kyri’s specialty area is ornamental fish.