Under £5
30 mins
Ages 3+
Fizzing garden volcano
Bicarb, vinegar and a lot of shrieking. Best done outside, trust us.
Science
Fizzing, popping, colour-changing experiments with things from the kitchen cupboard.
Free
10 mins
Ages 3+
Rainbow milk
One drop of washing-up liquid and the colours swirl like magic. Ten minutes, zero cost.
None of these match that filter yet. More ideas are on the way every week.