Ha yea, I know it's completely pointless, but I also cool the MB (2 blocks), RAM (2 blocks) and aquaero (1 block). And of course the CPU itself!

Hi, It's two separate loops, so each loop has just one pump. I'm guessing it's the sheer amount of resistance, CPU loop has 6 blocks and one quad rad, GPU loop has 3 blocks, one quad and one dual rad. Each loop also has an aqua computer filter (I don't think that makes much difference tbh)

Jackson, you were correct, the pumps do indeed spin down below 60% when the PWM signal is lost. I'll just run them at 100%, my flow rate is 0.66 GPM anyway!

Thought so thanks. One more question, if I ran both pumps from an aquaero fan header, would the PWM signal get interrupted during a reset like the mobo does, or would the aquaero maintain it?

Ah that's interesting, thanks for your reply.... I'm not sure that's correct but I'll give it a go and report back. My thoughts are when I set the pump to 100% in my MB fan control, it reports saying "PWM disabled" and the pump runs 100% all the time Otherwise its a case of buying a more sensitive flow sensor (not using them is not an option) or just leave the pump running 100%. First world problems! EDIT Out of curiosity, can you modify a mps400 to a mps200??

Thanks for your reply, it encouraged me to think of it another way and I think this may be the reason: https://community.futuremark.com/forum/showthread.php?182990-For-those-of-you-guys-using-a-D5-PWM-pump When the pump loses signal, it defaults to 60%, not 100. As I mistakenly brought the mps400 sensors, they can only sense 80l/hr min and I suspect at 60% power, it might be just enough to go below this flow rate and read as zero. I'll report back after some testing.

Hi all, First time posting on this forum - I've posted the below on the OCUK forums, I have a two loop WC build ran from PWM D5 pumps. The pumps are powered direct from the PSU and controlled from my MB fan headers via my bios fan control, running at a constant 100% speed. I also have an aquaero 6 controlling fans, monitoring temps and most importantly in this situation, monitoring flow rate on the aquabus which is set to execute an emergency shutdown if the flow on either loop drops. OK so ever...