Hi folks,

I seem to have run into trouble with my water cooling loop.

I built my loop around 6 months ago, everything is new, except for the pump which is being reused. Most parts are nickel plated, MCP35x pump, Bitspower acrylic reservoir, Primochill Liquid Utopia additive (which obviously didn't do squat).

A couple of days ago I found some black stains in my reservoir. I drained the loop.

The issue: there are some black stains on my acrylic reservoir, and plastic parts of the pump (MCP35x), and they are very difficult to get off. I've never seen anything like that before. Most of it is near the bottom of the reservoir, and is on plastic parts of the pump (for example, the blue impeller of the pump turned completely black, and it took a lot of rubbing to get its top back to normal). Some of it is on metallic parts and fittings close to the pump, but that was much easier to clean off. I have not opened the blocks yet, will do it today.

There is basically some sort of thin black film, which is fused with the surface, and it takes a lot of rubbing to get off. I tried using dish washing liquid, it's not helping at all.

So, here are some questions:

1. What is this crap? Is this some sort of algae? It's almost completely black.

2. How do I get it off? Some parts of the pump are impossible to reach without breaking it. Can I use some chemicals to wash it off without rubbing? I really don't want to buy a new pump.

3. After I clean it, is it safe to reuse the parts? Pump being the biggest issue. What if some of it, somewhere, doesn't come off? Will it spread across the loop?

Any and all help is appreciated.

Thank you.