Flushing

hello, i am building my first water-cooling loop and i am having trouble finding distilled water, for some reason its especially hard to find in the UK, would it be possible to flush my rads with tap water as i am using EK premixed coolant with anti corrosives in anyway? or do i need to buy some...

Just want your guys opinions on what is the better laptop. Both are i5-6300HQ, 8GB RAM, have a 1TB HDD and 128Gb SSD, and have 2GB GTX 960M. Not keen one either keyboards, I prefer chamfered keys that but up against each other, like I have on my Microsoft Wireless Keyboard 800, but does not...