Thanks for the info. Your tea should be brewed at about the same temp as your res. This way you end up breeding only those microbes which are suited for your res. So simply brewing it in the grow room at ambient temperature should be fine. Your res should be anywhere from 70-78ish, and so should your tea.
Matching the tea brewing temp with your grow medium temp is really more important for soil growers than DWC, but is still the proper thing to do. Now, don't worry that adding cold water to the res, or putting the tea in the fridge, will kill bennies. By then they have already been 'born', but too low temps during the brew can prevent them from being born, and too high temps can breed microbes that will not colonize in a lower temp res. Avoid extremes and you'll be fine.
New brewers should remember; the tea works really well even if your brew is not perfect. Just follow the basic recipe, wait for 48 hours, make sure there is no bad smell, and apply it. Do not worry about foam, slight temp variations, ect. Just add bennies, food and LOTS of bubbles and your tea will be enough to kill the slime. All this other information is just incidental tweaking.