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Lower Pump Speed with Low-Noise Fan Adapter?

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New Member
Oct 21, 2011
So I have the Koolance PMP-400 (Laing DDC 3.25) pump without PWM, just a single 3-pin molex power connector. And Im wondering if it would be possible to safely lower the speed of the pump using a low-noise fan adapter? The one from Noctua lowers a fan to 7 watts according to their website. I hate the idea of buying a 50 dollar fan controller just to lower the speed of one pump one time for permanent operation at that speed. Also, if the low-noise adapter successfully lowered the wattage of the pump- that would also lower the total amperage the pump pulls correct? Potentially lowering it to below 1 AMP so I could power the pump off a 1 AMP motherboard fan header? Thanks for any help!


Water Cooling Senior Member, #TEAMH20HNO
May 22, 2011
I'm don't think its possible without damaging the fan header on the MB. Most MB CPU fan header's average around 1 Amp at the most. This pump is a premium pump that either needs power straight from the PSU or a fan controller.

Now I'm not sure if you're able to use a lower voltage fan adapter on this pump. I'd check with Koolance on that. If you can't, there should be many fan controllers out there that can handle this pump because its only voltage controlled.


Senior Pink Member
Sep 13, 2015
Why are you trying to slow it down, noise?

If you are looking for a fixed position solution, I would just put a 25w 1.5 ohm resistor in series with the pump. It will put about 10.2 volts to the pump.

If you are looking for some control get yourself a 25w 2ohm rheostat and put that on series with the pump.
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