Coolant - deionised or distilled water?

[yokohama]

I'm going to do a coolant change on my K4 and have some of the Halfords red concentrated.
As per the title really. Should I mix with deionised or distilled water? Does it really matter which?

[Bibio]

does not matter as both processes remove the minerals. if you have a RO filter you could use the water out of that.

[andrewsmith]

Most is premix TBH.
I normally use a little bit of de ionised to finish the flush for new coolant

[yokohama]

Thanks guys. I've a bottle of deionised somewhere so I can use that.

[johnnyrod]

See the other thread - if you have anything at home that condenses water e.g. condensing tumble drier or a dehumidifier then you have a source of distilled water. For the coolant system you're only looking for most of the mineral stuff to be removed so don't worry about what sort of purified water it is, anything will be good enough.