To answer some of your questions:
I am using mineral oil. Though around here the only mineral oil that I can get local is used as a farm animal laxative. I can order it online, but the shipping kills me. One Gallon jugs are already $15 each and this rig is using a 20 gallon tank, though only using 15 gallons. There are videos of people using vegetable/cooking oil, but while its cheaper, you have to change out the oil after several months. Mineral oil, if kept covered, should last years (tested by one company for over 5 years to date)
The setup was not that hard. I was going on ideas and guesses. I could have bought the kit from a company for $500 but it would only hold 3 dbl slot cards. Since I was piecing it together there was a lot of error to get pieces right, but with experience I know what to expect now.
The idea of submerging it for me at least, is the advantage that you don't need to buy water blocks for your cards. Each block can cost you 80-100 each, that is if you have a current video card. Since most miners (imo) use older cards, harder to find water blocks.
For me it was the fact that I could keep the computer in a "dirty" location, and not worry about the computer getting covered in dirt or bugs. Plus keeping it in the garage takes care of any noise issues. There is a night and day difference between air rig and oil rig with noise and possible heat, but there is also a 2x-4x cost difference between the air and oil. So it comes down to need or desire.
Ill post of a video of air rig and oil rig after I get my triple Rad installed and get the oil rig running at 100%. I think my issue is now that all the cards running 100% heats the oil up enough that it causes the USB controller on the motherboard to overheat and it reboots, but it hangs while initializing the USB controller. The big downside to the oil rig, is it heats up everything. So if one thing has a low threshold, then everything fails. The rig would work on air, if I had a box fan blowing directly through it (not in the tank). So I know it will work, just need enough cooling.
So expect some video this weekend.
Thanks for answering our questions, I am looking forward to the video

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