<< unfortunately mineral oil is at most .88 the density of water, and acetone is even less, so they'd most likely sit at the highest parts of the system, reducing the water flow noticeably
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partially incorrect..... the water flow would decrease b/c of the higher VISCOSITY of the oil, not b/c it floats on top of the water. As long as you have a good pump... the water flow will not be affected that much. You would be fine w/ the flow; its just your heat absorbancy that would be affected. If my memory hasn't failed me, oil's thermal conductivity is lower than that of water, so in the same amount of time, the oil is going to absorb and let off less heat, lowering the effiency of your water cooling system. It never hurts to try it out, it might look cool as hell but if your performance drops too much, forget it.... if you want some neato effects, find some synthetic water colors that won't break down due to 120 degrees F or so. That'll get the ladies go'in for ya 😉