I missed the ramblock in the gallery shot,
and how are you measuring Delta?
You seem to be taking core temps above ambient as the measure to me?
cpu 25'c above ambient, Gpu 15'c above?
your Delta is the difference between ambient and your water temperature and in a normal loop won't be more than 1-2'c different anywhere in the loop, if you have a 10'C difference in different parts of your loop I think theres a problem
just checking is all