Cooling water system options

[likesrocks]

After searching this forum and the web in general extensively, I am no closer to finding the answer to my question posted here:

http://eng-tips.com/viewthread.cfm?qid=213948&page=1

So I have linked it here since it appears that there is more activity in this area of the forum, and perhaps this is the correct place for my question anyway.

Thanks in advance for any help.