want to custom build my own coolant water system for my PC. I don't over clock my PC, I am doing it to eliminate fan noise(Dual Core Opteron system produces alot of heat and makes fan run high) and also because it looks so cool. I have some questions if anyone can help: 1) Which brand is better, Alpha Cool or Koolance? In my loop I will be cooling CPU and 2 hard drives(thinking about doing northbridge but dought it since I don't game). 2). I read on Koolance site that they recomand 3/8 hoses because in some cases 1/2 hoses can hurt preformance, how is this so? 3). How do I know what power/size pump to get? If the pump is to strong the flow of water will move to fast to cool off and if the pump is to weak then the flow of water won't move enough to cool. 4). How do I know what size radiator to get to cool my system but also to match the pump flow since it causes restriction to water flow?