How to Care for Your Pond Fish Through Autumn and Winter in Australia

If you've spent the warmer months watching your fish dart around the pond, feeding them daily and enjoying everything they bring to your water feature, the thought of winter can feel a little daunting. The good news is that with a little preparation and the right routine, your fish will come through the cooler months in great shape and be ready to thrive again come spring.

Here's everything you need to know about caring for your pond fish through autumn and winter in Australia.

What Happens to Your Fish as the Water Cools

As water temperatures begin to drop through autumn, your fish go through some significant biological changes. Their metabolism slows right down, their digestive system becomes less efficient and their immune system weakens, making them more susceptible to stress, parasites and illness during the transition.

This doesn't mean you need to worry. It's a completely natural process. But it does mean your fish need a little more thoughtful care through this period than they do in the warmer months. Understanding what's happening helps you make the right calls on feeding, treatment and water quality as the season changes.

A pond thermometer is a really worthwhile investment if you don't already have one. Monitoring your water temperature through autumn gives you a clear guide for adjusting your fish care routine as conditions change.

Feeding Your Fish in Autumn: Getting It Right

Feeding is one of the most important things to get right as the weather cools, and it's also one of the most common areas where pond owners make mistakes.

When to start reducing feeding When water temperatures drop below 15°C, your fish's metabolism and digestive system begin to slow significantly. At this point you should start reducing how much and how often you feed. Both our Premium Staple and Colour Enhancing pellets are formulated for water temperatures of 15°C and above. Below this point your fish simply cannot digest them properly and uneaten food will sink, break down and create water quality issues.

When to stop feeding altogether As a general guide, stop feeding your fish entirely when water temperatures drop consistently below 10°C. At this point your fish are in a near dormant state and feeding them can cause serious digestive health problems.

A few general feeding tips for autumn:

• Feed in the same spot each time so fish learn where to come and waste is minimised

• Only feed what your fish will consume within three minutes

• If fish are not eagerly feeding, take it as a sign the water is too cool and reduce or stop

• Store fish food indoors at room temperature and never use food that smells off, has changed colour or clumped together

The Right Fish Food for Autumn

Aquascape Premium Staple Fish Food Pellets Your everyday fish food for the warmer parts of autumn when water temperatures are still above 15°C. Formulated with high quality protein to optimise growth, probiotics to aid digestion and reduce fish waste, and stabilised vitamin C for overall fish health. Available in small pellets for fish 8cm and above, and large pellets for fish 20cm and above. Floating pellets help you monitor how much your fish are eating and make it easy to remove any uneaten food.

Aquascape Premium Colour Enhancing Fish Food Pellets If you want to bring out the best in your koi or goldfish heading into the cooler months, the Colour Enhancing formula is a beautiful option while water temperatures are still above 15°C. Specially formulated with additional vitamins to promote brilliant, vibrant colouration in your fish.

Keep the Water Healthy for Your Fish

Your fish's health is directly linked to the quality of the water they live in. As biological activity slows through autumn, maintaining good water quality becomes even more important.

Beneficial Bacteria Even as temperatures drop, keeping up with your beneficial bacteria dosing is essential for fish health. Beneficial bacteria breaks down fish waste and excess nutrients, reducing the ammonia and nitrite levels that can become toxic to fish if left unchecked. Our Beneficial Bacteria contains eight pure strains of concentrated bacteria along with marigold and vitamin B to support the natural colour and health of your fish through the cooler months.

Maintain for Ponds A simple, all in one treatment that combines beneficial bacteria, a phosphate binder, flocculant and pond detoxifier into one easy formulation. The detoxifier removes chlorine, chloramines and heavy metals from your pond water, keeping conditions safe and comfortable for your fish through autumn and winter. 

QuickFix Pond Gummy If you notice signs of ammonia or nitrite stress in your fish, lethargy, gasping at the surface or unusual behaviour, the QuickFix Pond Gummy is a fast and easy solution. Each gummy targets ammonia, nitrite and phosphate while helping to control organic waste, treating up to 11,340 litres of pond water. Drop one in and let it do the work.

Signs Your Fish Are Struggling

Knowing what to look for means you can act quickly if something isn't right. Here are some signs your fish may be under stress or experiencing health issues through the cooler months:

• Gasping at the surface, which often indicates low oxygen or high ammonia levels

• Lethargy or sitting at the bottom, which can be normal in very cold water but is worth monitoring

• Loss of colour or appetite, which may indicate stress or illness

• Visible wounds, sores or unusual spots, which should be treated promptly with Protect for Ponds

• Wider head than body, sunken eyes or pale colouration, which can indicate underfeeding or poor nutrition

If you're concerned about the health of your fish and unsure what to do, reach out to your local Certified Aquascape Contractor or a pond specialist for advice.

A Simple Autumn Fish Care Routine

When water is above 15°C

• Feed up to three times daily with Premium Staple or Colour Enhancing pellets

• Dose with Beneficial Bacteria weekly

When water drops below 15°C

• Reduce feeding frequency and stop using standard pellet formulas

• Continue weekly Beneficial Bacteria dosing

• Monitor fish behaviour and health closely

• Use QuickFix Pond Gummy if ammonia or nitrite issues arise

When water drops below 10°C

• Stop feeding entirely

• Continue Beneficial Bacteria dosing at a reduced rate

• Check on fish regularly for any signs of stress or illness

• Ensure your pond has adequate aeration to maintain oxygen levels

Fish are remarkably resilient creatures and Australian winters, even in the cooler southern states, are generally mild enough that your fish will come through just fine with a little care and attention. The most important things are getting your feeding right as temperatures drop, keeping water quality healthy and giving your fish the protection they need during the transition.

Come spring, you'll be rewarded with happy, healthy fish ready to enjoy another season in your pond. 

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