I will try to give you some answers on your questions.
1) Two water circuits are better of course but more expensive (2 pumps, 2 rads...) but if you go for a single circuit put the two waterblocks in parallel with a "Y". With a series connection your second CPU will always be hotter (10°C or more...)
2) Personally I prefer the new AquaCoil II with 1/2" connections, it cools better than the Black Ice (3/8" connections) and is less expensive (see Radiator Roundup at
http://www.procooling.com/reviews/h...on_1_-_8.shtml, although the tested AquaCoil was the old 3/8" version). Heater cores like the Big Mama work better and are less expensive but they are less compact and do not have fan or mounting holes.
It's also a matter of space constraints in your case.
3) Any waterpump is OK as long as it fits in your setup (hose connections, size...) Take a pump with at least a couple of hundreds of gallons/minute (mag drive pumps don't like back pressure, so the real flow is less than half or a quarter of the specified flow). The best are Eheim (but expensive and big) like the 1048 or the 1250. Danner pumps are fine but they tend to "rattle" (although there is a fix on internet on how to glue the impeller to the axle).
4) Inline is better for the temps (pump dissapates less heat to the water - even my inline Sicce Idra (25Watts) adds 5°C to the water with the radiatorfan not running!) and you don't need a real reservoir if you have a "fill & bleed" system with valves and/or an "airtrap" (see my threads
http://forums.procooling.com/ubbcgi/...c&f=2&t=000555 and
http://forums.procooling.com/ubbcgi/...c&f=2&t=000647
5) Definately Yes! (see my thread
http://forums.procooling.com/ubbcgi/...&f=2&t=000608.
6) Not at all.
6a) As far as the airflow of the radiatorfan is well ducted through the rad and then outside the case everything is just fine. I f you use one fan on the radiator make it "suck" air through the rad through a shroud. Axial fans have a dead spot in the middle and by using a shroud (about 1") the fan will be less noisy (less air turbulency). (see also my thread
http://forums.procooling.com/ubbcgi/...&f=2&t=000555.
7) 12V pumps are more expensive and more noisy.
Just use regular 110V AC pumps with a relay connected to the PSU. That way your pump is powered on together with the PSU and you can't forget to power on the pump. If you need help for the schematic just tell me.
7a) See 7.
8) AFAIK none, I use Purple Ice because it was easier to obtain in Belgium. Both are anti-algae, anti-corrosion additives and tend to drop the water temps by a few degrees due to the decreased surface tension of the cooling water. Use a mix of 2oz in 1 gallon of demineralized or distilled water.
9) Definately go for 1/2" tubing. Like I said before, mag drive pumps do not like back pressure, so use the biggest possible ID.
Try to not have an ID less than 9 to 10mm in the hole circuit (including waterblocks).
10) I like silicon hoses. They are very soft, do not kink that easy as PVC hoses and do not tend to become hard in time as the PVC one. Is more expensive and less transparent than PVC hose.
11) Aircooling on waterblocks is not efficient. Just use an automatic shutdown utility in case of pump failure (like Shutdown Now) when the CPU temp exceeds a predefined treshold.
A well build watercooling setup is as reliable as standard aircooling.
Of course, this is just my humble opinion.
CD
