FAN BUS Controller - Part 5 the reservoir

To increase the volume of the liquid in the watercooling system, I've designed a reservoir that should solve several problems with the old cooling system.
The idea behind the reservoir is first of all increase the volume of liquid contained in the system, which should help stabilization of the temperature. Secondly it should help when filling the system as any bubbles in the system should rise to the top.

So heres a picture of the system:-

And for all of you who can't imagine what it looks like installed. Now it's time to play spot the res :):-

And heres a picture from the back so you can see the reservoir :-

part 6 - Tank Level Monitor