Those temps are really good. The Intel based CPU's and MB's are designed to withstand a lot higher temps. My i7-3770 idles around 40C with the stock cooler, which isn't bad.
How hot is your i7 4790k running in games and in idle.
Those are normal for a water-cooling loop. Mine iidles around 22-24C, load is around 55-60C, with a Noctua NH-U12S (air cooler) in the "standard" (quiet) cooling setting, with the processor not overclocked