Anyone knows where to buy distilled water by the gallon?

Looked everywhere for that but none found.only found mineral spritzer and normal filtered one

Premix are 50:50.i want to run lower coolant percentage for better cooling

Water is the best for heat transfer.coolant is there to protect against corrosion and provide some lube for the water pump

Thanks.i'll have a look.a lot of simple stuff sold abundantly in other countries yet very scarce here.makes diy works quite a hassle