New loop - problems

[yndy]

I set up a custom loop in my new pc about a week ago. It worked perfectly for a few days but then the coolant suddenly turned very cloudy. When turned off it becomes clear again, but when running it quickly turns almost opaque. It's distilled water with a silver kill coil, I'm fairly sure there's only nickel, copper and brass in the loop. I rinsed out the radiator thoroughly before installation, but the rest I only ran water through briefly.

Does anyone know what might be causing this, and whether it's a problem? My temps seem alright (50-60 degrees with a i7-3770k @ 4.0Ghz under load).

I've also been noticing some rather suspect noises coming from the computer, but I haven't been able to pin down what component is causing them. Thudding, clicking and also a sound like a record skipping that's sometimes accompanied by a brief screen freeze.

I'd really appreciate any help, this is my first computer build and I've no idea what I'm doing D:

 

[yndy]

wow thanks for the quick response.

I checked all the fittings, there's definitely no water getting out so I don't see how any air could be getting in, other than the air at the top of my reservoir. It's an EK dcp 4 pump with the combo reservoir, so it's hard to see what's going on. Do I need to take the whole loop apart?

 

[yndy]

I bled the loop again, it seems to have reduced (though not eliminated) the bubbles in the fluid, and I'll listen out for any more suspect sounds. Thanks for the advice