I have two computers with water cooling systems. Both are cheapo kits I bought off of amazon. One computer is on the floor the other is sitting on a desk. Both have same number of fans and the CFMs vary.

System one
Evercool water cooling pump/tank/radiator.
Thermaltake water tank, uses one drive bay.
Evercool water block.
Special custom coolant  ;D
Lowest temp 65.7*F (this is the temp from when I turn it on around 6:30am to about 10:00am)
Mid temp 81.4*F (this is the temp when it's been on all day)
Max temp 90.0*F (after i've played games for a few hours)

System two
Evercool water cooling pump/tank/radiator.
Evercool water block.
Evercool 8 pass radiator.
Koolance Liquid Coolant
Lowest temp 71.5*F  (this is the temp from when I turn it on around 6:30am to about 8:00am)
Mid temp 90.1*F (this is the temp when it's been on all day)
Max temp N/A (Server, doesn't play games. Used as HTTPd, FTP and SMTP)

Heres the pros of water cooling.
System/s run far much cooler and perfect for mid range over clocking.
Makes the computer look sweet.

Now for the cons.
Always have to top off the coolant once a week or the pump will run dry and break.
Building the system you have to make sure the hoses have no leaks.
Building the system you have to make sure you have proper flow, no big drops or climes.
Can't run system 24/7 or the pump will over heat and break. Most pumps need at lest a 4 hour break every 24 hours.


Heres a tip for coolant. The so called coolant for water coolers are a joke. Also some will bleed all over the hoses so you can't see it flowing anymore. I have found using distilled water and royal purple's Purple Ice radiator treatment works very very well.

I would say that the only problem is that it costs more than good air cooling.  If your system is tight, you should only have to top off once or twice a year.  All of the pumps I have used had no problem running 24/7.  In fact, a workstation I built for a friend is always running and has never been topped off.  High quality kits or parts do make a difference.  IMHO, budget kits cannot compare to hi end heatsinks.

Your temps look pretty darn good though. Is 65.7F below ambient room temp?  That would be really impressive.

The computer room has been staying at a steady 75.3*F but in the afternoon it's around 82.1*F for like 4 hours.

Every water cooling kit i've played with the manual says to give the pump a 2 to 4 hour break every 24 hours. you can have the worlds cheapest kit and it could out perform a high end system. Just depends how much the pump can push and how deep the water block is (deep as in how close the coolant travels to the bottom of the water block).

I need to get a new water block. The one im using now on system 2 is a GPU water block and it's pretty shallow. I have two pumps on order that are made for pounds but it will work with my setup. Just need a 1/2inch to 3/8inch fitting for each pump.

Most hi end kits push a lot of water.  About 300g per hour is ideal.  Also, the best water block today use a pin matrix design.  This gives them more surface area and increases turbulence in the cpu die area.

Can't leave the system on 24/7?  That is a HUGE con for me.

I would assume that not all pumps suck that bad though.  I would imagine the pumps you have been using are not very good.

Saying you should shut down every water cooling system for 2-4 hours would be like saying my friends quad G5 needs to have a break for 3 or so hours before it to run for the next 21 hours.

And BTW his machine has been up non restarted for 47 days now...

True, you should not have to shut your system down ever if you dont want too.  That would classify it as unstable.

Any kind of cooling system (passive or active) is crap if you can't run it 24/7.  Its been proven over and over that computer hardware lives longer if always on and you need a cooling system that can match that.  Otherwise..  its just masturbation.