Mag 18 cavatating?

[banditpowdercoat]

OK, testing my tank again. Little different design. I put the MAG 1800in the overflow, and made a true closed loop with the header. Then, I am using the canister fro the filter. No spinge or nothing, most likely UV sterilizer or rubble in there. But anyways, testing the sys with freshwater. Mag is kinds noisy. Rattling sound and a ton of microbubbles with it running. Like its cavitating?!?. Is that possible? How long before the water clears itself of the bubbles that cling to the sides of the glass, etc? There is only a 1/2" drop over my overflow so bubbles are not being introdiced that way. The pump is set up with 18" of 3/4" hose to the manifold. No real head pressure either. Gets good flow/circulation