sump advice?

[frd72]

i notice tonight that there were tiny bubbles on top of the water in the sump. i only divide it into 2 compartments,1 for drain and the other one where the return pump and skimmer sits. Basically you barely see water movement at this compartment. do i need to put power head just to have movements and prevent the tiny bubbles..or are this normal and nothing to worry about??

thanks in advance

teddy