I back up the above with some maths
HERE (OCAU's new Wiki).
Unless you're dealing with very low flow rates or a killer rig (peltiers, multiple CPUs/GPUs etc) and hence dumping hundreds of watts into the coolant, the temperature rise will be miniscule.
Also, I'll add that the NB and HDDs will not care a jot about water slightly warmer than how hot you'll want to run your CPU (and possibly GPUs) at.