API pH Down - 118mL

Keeping the right pH is an important part of maintaining a healthy freshwater aquarium. API pH Down is a liquid pH-reducing solution designed to help lower aquarium pH when your water is testing higher than the level suited to your fish.

Different fish have different pH preferences. For example, many community tropical fish do well around neutral pH, while some Amazonian species such as neon tetras and angelfish prefer slightly more acidic water. Goldfish and many livebearers generally prefer a higher pH.

API pH Down can be used when setting up a new aquarium, when adjusting water conditions or when making water changes. It is safe for fish and aquarium plants when used as directed.

How to use API pH Down

Always test your aquarium water before adjusting the pH. API recommends adding 2 drops per 3.8 litres (1 US gallon) of aquarium water, then testing the pH again before adding another dose.

Some fish can be sensitive to rapid pH changes, so avoid making large adjustments in a short period. As a general guide, changes greater than 0.2 pH within 24 hours should be made with particular care.

If your water has high levels of carbonate or bicarbonate, it may be strongly buffered. This can make the pH resistant to change or cause it to rise again after treatment. In these situations, repeated small adjustments may be needed rather than one large dose.

Why test your aquarium water?

Your aquarium's pH can change over time due to factors such as fish waste, uneaten food and the addition of tap water. Regular testing helps you understand what is happening in your aquarium rather than adjusting the pH based on guesswork.

For best results, test your aquarium pH regularly and make gradual adjustments when needed.

Frequently Asked Questions

What does API pH Down do?
API pH Down lowers the pH of freshwater aquarium water, helping you adjust water conditions to better suit the fish you keep.

How do I use API pH Down?
API recommends adding 2 drops per 3.8L of aquarium water, then testing the pH again before adding another dose.

Can API pH Down be used with fish and plants?
Yes. API pH Down is designed for freshwater aquariums and is safe for fish and aquarium plants when used as directed.

How often should I test aquarium pH?
Regular testing is recommended, with API advising weekly pH testing to monitor your aquarium water.

Why won't my aquarium pH stay lower?
If your water contains higher levels of carbonate and bicarbonate, it may be strongly buffered. This can resist pH changes or cause the pH to rise again, meaning smaller repeated adjustments may be necessary.

Wonderworld Tip

Don't chase a particular pH number just because it looks good on a test kit. The best pH is one that suits the fish you keep and stays stable. If you're unsure what pH your fish need, bring us a water sample or have a chat with the team at Wonderworld Aquarium & Pet Centre. We'd rather help you get the water right than have you continually adding products to chase a number.