The problem
Dusty leaves are more than a cosmetic problem. A film of dust blocks light, which slows photosynthesis and dulls the plant. Hard water makes it worse, leaving chalky white mineral spots on the foliage that a damp cloth simply smears around.

The hack
The acids in white vinegar, or lemon juice, dissolve the mineral salts left behind by hard water – just wipe a very diluted solution over the leaves with a microfibre cloth.

The method
The popular version of this hack recommends a one-to-one mix of acid and water, which I think is far too strong and risks scorching your leaves. Instead, use roughly a teaspoon of white vinegar or two tablespoons of lemon juice to a litre of water. Mix it up, dip a microfibre cloth, hold the underside of the leaf with one hand and wipe gently with the other, top and bottom.

The test
I mixed a weak vinegar solution and used it on a peace lily blotched with hard water marks. The chalky spots lifted cleanly and left the leaves clean.

The verdict
This one works, but the internet’s usual recipe could ruin your plant. Kept very dilute and used only occasionally when hard water marks build up, a weak acidic solution is a useful way to get leaves clean and healthy.