Cloudy coolant

[OM222O]

First time building a PC; as soon as I turned on the computer, the water went from clear to cloudy which I suspect isn't normal. I have posted an image and video on reddit (sorry for using a link, I didn't want to re-upload) : https://www.reddit.com/r/watercooling/comments/1iuwsoo/cloudy_coolant/

Does anyone know what caused this and what I should do about it?

 

[OM222O]

I bought 10L of deionized water and flushed the loop a few times and it looks clear (either the micro fins did a great job of filtering out the gunk or I actually managed to get it out). It looked oily so it was probably o-ring lube (it wasn't on any of the fittings / res / pump as far as I can tell) or machining oil left in the CPU block. Is running just deionized water fine or do I absolutely need the additives? I plan on redoing parts of the loop in a month or so when I can get a GPU block for the 5090 so was gonna clean the CPU block and re-fill with coolant then, but I'm a bit worried about running it for 2 months without corrosion/growth inhibitors.