I have a PID running a SSR that controls my heating element in my RIMS tube. It is a 25 amp relay and the element is 1500 watt (12.5 amp). I have been using this system for about two years and the relay always ran quiet..the last brew session it started a humming noise when the element is on...
WOW, 1.5LBS/GAL is 2.6qt/lb seems to be a pretty thin mash.
I use a 1.3qt/lb ratio for mashing normal grain loads
I use a 1.15qt/lb ratio when I max out my grain load @ 35lbs
As far as sparging I fill the HLT (15gal) and sparge till I get my desired boil volume making sure to check...
black malt provides a harsh...burnt... dry...charcoal taste, as roasted barley provides more of a roasty...coffee warmth. RB also adds complexity to the beer due to its available starch from not being malted. I like roasted barley personally. Its all in what YOU want your beer to taste like...