Bach-On!!!
Thanks for the concern
I'm not sure it would be an issue in a closed loop system but I suppose if it running just water with no antifreeze then a UV light Passover, (like for ridding a pond of algae) would be a wise addition. The PC cooling system will be 40% antifreeze so I doubt much would want to live in it.
I'm not sure the cooling house thing would work but air at 8°C (46°F) sure would feel nice and cool if it the ambient were in the high 30°C's (100°F)
resago
True, but the temp below ground up to a given depth will be related to the average surface temps. Soil or earth is a pretty good insulator when dry, and this is what could cause the issue. If the heat produced by the PC cooling over time, especially if it were using peltiers and running continuously, could slowly raise the soil temp around the tank. If so the coolant in the tank would rise and so on. If the soil was wet however it would transfer the heat away far better and I doubt heat up could be an issue.
This is all theoretical of course and the cylinder I'm going to use will be about 80 litres in capacity so it should not be a problem. As my water table is only 5 foot down I may as well immerse it.