I finally bought a protein skimmer over the weekend (Red Sea Prizm Skimmer).
I was very excited to get it up and running (especially when I saw all of
the gunk it skims out of the water). I hope this means I won't have to do
those 50% water changes every single week now!

it very well could, the scarry part is why are you doing such a high waterchange so often,
you shouldnt need but 10% weekly or 20% bi-weekly even in a system w/o denitrification,
its either excessive or you have a problem you forgot to mention.

Anyway, my question is this...when I bought the skimmer at the LFS, I asked
the guy helping me if the skimmer added any additional aeration to the tank,
and if so could I remove my airstone. He said absolutely, but I'm nervous
and wanted a second opinion. I don't want to deprive my pets of oxygen. Do
my filter and protein skimmer provide enough aeration to the tank, or should
I put the airstone back in?

owning a bio wheel in the first place cuts your need for an airstone/directed powerhead
significantly

the first steps towards processing waste require oxygen, rapidly out competing any fish
needs. in your case there being done on a device that is not submerged which is the only
way to prevent some level of competition for oxygen with the fish this is why/how bio
wheels do such a good job, plus they generally pour into the tank moving the water at the
surface, even without the benifit from the bio wheel, any HOB filter will move enough
oxygen for your 29 with low bio load.

the most likely bad advice was from the one that said you *need* it for oxygen exchange.
the only possible exception i can think of is if you ran a plennum, in which it wasnt bad
advice, just advice with a gap of information that you were either to new to process, or
were not informed about. if you went to any of MY lfs's the later would be way more true.


HTH
--
richard reynolds