Ever wonder why you should not be in a hurry to refill your radiator with just any water, yes i meant just any WATER!!!
Part of your routine check should include your coolant (i.e. anti-freeze) level and you should not form the habit of just constantly refilling the coolant every time, rather consult a qualified personnel to check the cause for you.
So you are wonder why not water? Except for distilled water, water is found to have among other minerals Calcium Ca of which the quantity varies based on location.
Am sure you are familiar with effect of repeated boiling water in any aluminum or steel container, overtime a whitish deposit noticed know as Limescale.
Amongst other Limescale effect on your radiator is clogging of coolant passage which will eventually lead to overheating and overheating is bad for your car.
Bottomline use approved coolant for your car and if you are not using a premix use only distilled water.