Finally I found the best pump configuration for this chiller. Two Iwaki MD-15R pumps connected in series - that's the best choice. I can go up to -25C with three water blocks with mix, which I posted in my last post in this thread.

I've done some good scores using this equimpent in last two months:

http://hwbot.org/submission/2302430_...gt_30011_marks
http://hwbot.org/submission/2302431_...gt_89018_marks
http://hwbot.org/submission/2312776_...90_26897_marks
http://hwbot.org/submission/2310129_...gs_33984_marks
http://hwbot.org/submission/2309934_...gs_14523_marks

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