I would not water cool in the S340 unless its and aio cooler. I tried cooling with my loop and it was a nightmare and looked horrible. I had to have my pump just sitting there in the open. My fans would not fit on the from radiator with the reservoir on the bar. My other two 120mm radiators would not fit on the top or back due to my motherboards headsinks for vrm. It was just an absolute nightmare with watercooling. I returned it right away and got a Corsair 750D. Personally I like the 750D better but it is double the price and Its much bigger since its a full tower case.