Extreme Watercooling - two pumps - different speed - is it okay?

Greetings guys,

Yesterday I post-assembled my extreme watercooling rig. I would like to know one thing. I have two variable speed pumps. Can one run on different speed, than other? They're both in the same expansion tank, so they're parallel.

Thank You for Your anwser!

Regards

uplink

P.S.: Reason is, that in this combination, they're inaudible, in every other combination, or same speeds they're audible.
 
Thank You for Your answers guys! Actually, my question is whether different speed won't damage the second pump, or something, when it will push liquid faster into the loop.

I don't have the second pump for higher liquid flow, but for redundancy, that's all :)

Thank You once more, and please lemme know if I won't damage the loop with different speeds with parallel pumps.