worn impeller housing?

[blacknife]

My return pump was putting out lots of micro bubbles, so i figured i would try to clean it.

turns out there is not much to clean to it unless I am missing something.

there was a piece of egg-crate or something in there.. white plastic i believe i got it out. the housing is all one piece and i can not figure out how to separate it though i can see where there is rivets or something where they pressed it together.

the impeller has what seems to me like a lot of play in it, so I guess my question is how much play should the impeller on a once piece pump housing have when it is off the motor?

I have no backup so i guess just put it back together and hope for the best, I guess either what its time to shop for a replacement/upgrade.

BTW the pump is a customsealife model 77840, blueline? bought them out a few years ago.
Edit:
blueline velocity t4
http://www.google.ca/url?sa=t&rct=j&...nlBMOw&cad=rja
guess the housing does come apart... now just to figure out what Worn means