Hey VoidObject, love the tutorial bro. DWC is so simple in design it amazes me that it even works when you see how complicated some of the other systems are. Anyway just thought I would throw out some advice since it happened to me recently. I went in to my tent to change a res and low and behold no F'in bubbles, plant was looking terrible almost like a drowned soil plant. Found out one of my older pumps went out leaving two of my reservoirs without air! Man I was so pissed.
I also run two stones in each resevoir so to correct this I decided to run each res off of two pumps, meaning each stone gets air from a different pump. This gives me redundancy now so if one of my pumps goes out at least one stone is still pumping in oxygen. Now, I know in a power outage your still SOL but I hope this helps because these pumps do fail and if it goes unnoticed too long well you know...
Also anyone that experiences high reservoir temps in DWC I recommend trying a cooler as a reservoir and if your still too high then add the frozen water bottles. Using the cooler also helps making trips to the freezer less frequent.
KnB