Caring for your aquariums and household appliances
The tap water we supply is safe to drink. However, it may affect your aquatic pets and some household appliances.
The following information explains how your water quality management can impact fish tanks, ponds, and appliances. It also provides tips to help you keep your pets and equipment in good condition.
Using tap water for your aquatic pets
The health of aquatic animals in your fish tank, aquarium or pond—like hermit crabs, frogs, snails and turtles—depends on many factors, including water quality. Tap water and its compounds are a few factors that need to be managed.
These tips give general advice on how to keep your fish tank, aquarium or pond water safe. They do not replace expert advice from your pet shop or aquarium specialist.
To help protect your fish and aquatic pets:
- Do not add tap water directly into your fish tank, aquarium or pond.
- Check your local water quality by viewing your drinking water profile.
- Ask your pet shop which water test kits and water conditioners are best for your tank, pond or pet type.
- Test your water regularly, check pH, temperature and free ammonia levels often. Adjust the water if needed, based on advice from your pet shop.
- Change small amounts of water often, no more than 10–20% at a time.
- Prepare tap water before adding it to your tank or pond. Follow your pet shop’s instructions. You can do this in a clean bucket.
- If your tap water has chlorine, follow the directions on the water conditioner label.
- If your tap water has chloramine, extra steps may be needed. See below for more advice. You may need to use more conditioner than the bottle recommends.
The importance of preparing tap water
If you use tap water without preparing it properly, it can upset the nitrogen cycle in your fish tank, aquarium or pond. This can cause ammonia levels to rise and become toxic to your aquatic pets.
This can happen faster if your tap water is chloraminated, because it often contains free ammonia. Even if you use a water conditioner, some free ammonia may still be left in the water. Most common water conditioners do not remove it completely.
Water changes also affect the water quality in your tank or pond. To help protect your aquatic pets:
- Change only small amounts of water at a time.
- Replace no more than 10–20% of the water during each water change.
Key points for your aquatic pets’ health
Ongoing water quality management is key to the health of your aquatic pets. Regular testing of your fish tank, aquarium or pond water is essential.
Most of the tap water we supply is disinfected with chlorine or chloramine. This makes the water safe for people and animals to drink. But these chemicals can harm aquatic animals, so they must be removed before the water is added to your tank or pond.
When to treat tap water
Treat tap water every time you add it to your fish tank, aquarium or pond. This includes regular water changes.
How to treat tap water
- Use a commercial water conditioner to prepare the tap water before adding it to your tank or pond.
- Do this in a clean bucket.
- Check your drinking water profile to see if your water has chlorine or chloramine.
- Ask your pet shop or vet which products are best for your water type and aquatic pets.
If your water has chloramine
- You may need to use more conditioner than the label says.
- Be careful if the conditioner has other ingredients—high doses may harm your pets.
- Many conditioners do not remove free ammonia, which is often found in chloraminated tap water.
Always follow your pet shop's advice to keep your aquatic pets safe and healthy.
If the pH or temperature in your fish tank, aquarium or pond is not right, it can increase the amount of free ammonia in the water. Free ammonia is toxic to aquatic pets when levels are too high.
When to check
- Test the water straight after a water change.
- Keep testing regularly and adjust if needed, based on advice from your pet shop.
How to check
- Use a pH test kit, thermometer, and heating equipment.
- You can get these from your local pet shop. Ask what’s best for your tank and pet types.
Different types of aquatic animals need different pH levels and water temperatures. Your pet shop can help you find the right range.
Tip: Tap water that has chloramine may have a higher pH level. Be sure to test it before adding it to your tank or pond.
Ammonia is a natural part of fish tanks, aquariums and ponds. It comes from fish waste and rotting material like uneaten food.
High levels of free ammonia are toxic to fish and other aquatic pets. Most water conditioners don’t remove free ammonia. The best way to manage it is through a healthy nitrogen cycle.
This applies to tanks and ponds, no matter what type of water you use.
When to check
Test your water regularly, including when you change the water.
Follow your pet shop’s advice to keep levels safe.
How to manage free ammonia
Your pet shop can help you choose the right option for your setup and the types of pets you keep. Options may include:
- Aquarium gravel or other products that help grow nitrifying bacteria, which support a healthy nitrogen cycle.
- Granular carbon filters that may help remove free ammonia.
- Aquatic plants, which support a balanced nitrogen cycle and make your tank look better.
- Ammonia removal resins, which can reduce free ammonia. These may need a higher dose if your tap water has chloramine.
- Products with good bacteria (called bacterial inoculums) to help balance the nitrogen cycle.
Ask your pet shop for advice that suits your tank or pond.
Caring for household appliances
Some household appliances may need extra care depending on your water quality.
Appliances that can be affected include:
- hot water systems
- dishwashers
- steam irons
- kettles.
To help protect your appliances, read the instruction manuals. Check for any advice about water quality, especially if it mentions water hardness, chlorine, or naturally occurring iron.
To learn more about your local tap water—like its hardness or pH level—go to your drinking water profile and enter your postcode. You'll find the most up-to-date information about your water.