DIY skimmer question

[ItsMee]

If a skimmer is plumbed from a needlewheel pump inside the tank, up over the side of the tank and down into an external skimmer, would the bubbles be able to travel downwards into the skimmer body, or can they not travel down?

Question simplified: Can bubbles produced by a pump be forced down a tube or will they linger within till they pop? The reason I ask is because I know thier natural tendency is to travel up.

[comatose]

if the water flow down is much more than the bubbles flow rate up then, YES

Just look at the beckett designs and you'll see what i mean.