xcraft:
thanks for stating the obviousthey fix it, but it is an old apartment and keeps breaking
The obvious needs stating more clearly since you still seem to be missing it: if they 'fix' it and the problem returns, they have not fixed it properly. Every time it leaks this will damage the property you're in. Having recurring leaks in a property is not acceptable either as an owner or an occupier. The correct solution is not for you to get a more efficient way to tell them the leak has come back - it is to put the onus on your landlord (if you rent) or the landlord above you (if you own) to actually properly fix the leak.
Or, carry on with your head in the sand, put a bowl on the table to catch the drips, put a spoon of salt in to ensure it's a conductor and put two wires in it connected to an arduino to measure the resistance, and raise an alarm as sooon as the resistance drops - and continue to let them walk all over you.