Houseplant hacks: does fish tank water work as fertiliser?

The problem

Houseplants need liquid fertiliser, but this can be expensive. Fish tank owners, meanwhile, produce litres of nutrient-rich water during water changes, which then gets poured away. Could it feed houseplants instead?The hack

Water from a freshwater aquarium contains nitrogen, phosphorus and beneficial bacteria. Rather than discarding it during routine water changes, use it to water your houseplants, giving them a free feed.The method

Only use water from a freshwater tank that is changed often. Collect the water during a partial water change. Allow it to reach room temperature before using it on your plants, then apply as you would any water with liquid feed.The test

I used aquarium water on a monstera and a peace lily for a month. Both plants showed healthy growth, and the peace lily pushed out a new leaf. The water did have an odour, but it faded quickly.The verdict