Iwaki RD-series power supply questions

I've got a pair of Iwakis just lying around, that I sort of want to use. Now, these things add alot of heat to the loop at full 24V, so running it at a lower voltage is probably wiser. I'm not making huge ass loops, at most 4 blocks and two Monsta's (240/360) or perhaps triple PA120.3's. I do have the trusty, old, Meanwell S-150-24, but then I'm stuck with the full 24V - unless I can somehow reduce the voltage. I know I've read that people run these at 18V, but not how :D The 2nd option is to grab an S-150-15, which should be adequate, I guess. Any thoughts?

PS: where does one buy these pumps these days? Someone in a local forum was wondering where he could get one.

I am curious for someone wise about this to reply and help you out due to Iwaki being sort of like a Chevy V8 of water-pumps, I guess, and I'm wondering how they are nowadays. Never owned one, but back in around 2007 was planning to implement it in a loop based on experiences shared here at XS.

Check this out: https://endless-sphere.com/forums/vi...hp?f=2&t=42793

I have an RD-30 with a S-150-24. The adjustment pot drops it down to 20.5v which was enough to save some power and heat for me.

I ran RD-30 @ ~20v with a pot off Meanwell back in the day. I wouldn't go below 15v or you are just wasting potential and modern rads can handle the little extra heat from the pump no problem.

http://martinsliquidlab.petrastech.c...mp-Review.html