This is a mineral oil submerged computer. Mineral oil is a liquid that looks and behaves like water but does not conduct electricity, hence why it is safe to run electronics inside it. The mineral oil also aids to control the temperature of the entire system, by soaking up and removing heat away from hot components like the CPU.
You might have already seen my first computer, which was also an aquarium computer. Something mighty unfortunate happened to it… This new aquarium computer is built with all the lessons learned from the first. Please continue reading to find out the details