bubbles (air?) in return line

[minermom]

I'm really new at this also, but I have lots of questions.....most of which I can find the answers to on the forum.
Does anyone have bubbles (air) come in the line when you switch from high to low on the pump?
We have an 18x38 Doughboy with a .5/1.0 Hayward pump. (Is this a big enough pump for a pool this size??) When I switch from high to low on the pump, air bubbles come in the pool for a few minutes, then go away and filters normal.
Any ideas?
Thanks,

[waste]

Minermom, first let me welcome you to the forum and congratulate you on caring enough for your investment to come here and learn the right way to take care of it without having to rely on 'pool pros' who may or may not know what they're doing, chemwise.
The sizing of the pump is, in part determined by the size of the filter - if you could let us know the filter size and type we can give you better info. As for the air bubbles, it seems harmless and corrects itself quickly. I'm no expert on this stuff but, the sudden loss of pressure may be causing a connection on the effluent side of the pump (anywhere up to the pool return) to draw air back into the system which takes a few minutes to pass - ** this is not to say that you have a leak (water loss), that would be fairly obvious on an AG pool, just that some connections might loose their seal when water tries to pass the opposite way from what they seal. ** - I haven't explained this very well, but I've seen it before. If you have any further questions - I'll keep myself at your beck and call - WASTE