I used primochill sys prep before I put in the coolant and I flushed the rads before that with distilled water. I had no coolant before as this is a brand new loop.Did you have any kind of coolant in there before? A clear coolant shouldn't turn cloudy.
Did you use any kind of pre cleaner in you loop? New radiators at least should be flushed before use, they will almost always have residual stuff in them from the manufacturing proces to include random grit and junk.
I honestly wouldn't buy any of EKs coolants. I had issues with thier opaque stuff a couple of years ago, but even their clear coolant shouldn't get cloudy on its own.
I like XSPC ec6 clear and aquacomputers Double protect.
Distilled works as well, but if you have any non nickel plated components, like the copper cpu plate or copper/brass then it really stops being distilled after a while as it strips ions off the copper/metal blocks. That is just reality. I used distilled/silver for years as well, it is definitely the cheapest route but nowhere near the best.
Going distilled is fine, just add in some form of corrosion inhibitor.