I have heard that the loach can be too rough as they get older.
Check some different sources for your pandas. Wild pandas and pandas bred in the aquarium by decent breeders are not sensitive. It is the fish that are bred enmass with hormones and mass breeding practices that are sensitive. They are also smaller, but they are not as hardy.
If you are in the States, Aquabid is a good source. Aquariaman, Coriologist, and CorysRUs all have pandas up, I believe, and are excellent sources.
If you are in the UK, ebay and Trimar are good sources I understand. As Alex and Carmen said, if you are getting them from the lps/lfs then watch them and look for good hardy specimens--doesn't hurt to ask what the source was.