Pump mounting
 

What do you say guys, is there a big difference between mounting my Eheim 1250 on the bottom of my case compared to somewhere in the cd-rom cage? I mean in head and flow. It's probably a 30 cm height difference.

If you are running a closed loop system, it shouldn't make any difference. The energy expended to overcome gravity (lifting the water) one side of the loop is returned as gravity pulls the water back down on the other side. Finding the best layout, which minimizes bends, fittings and tube length can help reduce flow resistance thereby increasing system flow and potential heat transfer... :)

I personally say, the lower the better.

My opinion is that even in a closed loop system, the pump will still have to "suck" water into the inlet if it is higher than the lowest point in your system and you dont want your pump "sucking" at all.

If you have a res. near the top of your system and your res. is feeding water to the inlet, than having your pump at the lowest point is a must.

Like I said, this is my opinion. No i dont have any proof other than water wants to travel to the lowest point and stay there :)

Well, in either case, the res will be placed above the pump. I just thought that pumping water upwards was worse, but the difference might be small.
It's a more a question of loosing pci slots/cd-rom slots now =)