I had my radiator cleaned and flushed yesterday. The mechanic who did the work advised that pure distilled water is better than using mixture of water and coolant. I checked the manual and it just mentioned that you need to pour in coolant but is not specific of the requirement (e.g. ratio, coolant type etc.). So out of curiosity, I checked online and of the many threads I've read, I stumbled on one of our own: Using only coolant or mix of water for radiator?. According to this thread and many more, it is advisable to use 50/50 antifreeze to water ratio.
Now, my question is if this is the case, do I need to flush my radiator again and change all the coolant to make sure that the antifreeze and water ratio is correct? Or is it safe to add coolant little by little?
Btw, I have no problem in freezing since there's no winter season here in my place.