Tap water is treated to be safe for people, which is exactly why it's a problem for fish and other pond life - chlorine and chloramines that are harmless to us can be harmful to them. Any water going into a pond from the tap needs conditioning first, not just topping up.

TetraPond AquaSafe makes tap water safe for fish and other pond inhabitants by neutralising chlorine and chloramines, and it immediately binds toxic heavy metals such as copper and cadmium. Tetra say its organic colloids protect the fish's delicate mucus membrane, and it includes vitamin B1 to support a healthy immune system and help fish cope with stress. It's intended for making pond water safe after heavy rainfall, during a partial water change, or when filling a pond for the first time.

• Neutralises chlorine and chloramines
• Binds toxic heavy metals including copper and cadmium
• Contains vitamin B1
• For use after rainfall, partial water changes, or initial pond filling
• 250ml bottle

One thing worth knowing. Tetra don't give us a dosing rate by pond volume on the information supplied, so check the bottle's own instructions for how much to add relative to the size of your pond rather than guessing a quantity.

Who it's for: pond keepers adding tap water to a pond for any reason - a top-up after rain, a partial change, or filling a new pond - who want the water conditioned before fish go anywhere near it.