I am no expert on water cooling a PC, but i have done a bit of research, and I am keeping things here for my reference
1- Do use distilled water, there is nothing wrong with it, unlike what people who sell coolant will try to tell you, it is working perfectly for me, I added about 20% car coolant to it for both color and other relevant properties
2- BOIL the distilled water to get the oxygen out of it, otherwise, over time the water will become still in the system, forming bubbles.
My pump already has a small reservoir
The system is very simple, Pump to block to radiator then back to pump, took much less time to assemble than i thought