I am in urgent need of help. I am looking after my boyfriends Mollies while he's away, hence I don't know any details of nitrate etc. readings (he's due back on Tuesday!) A couple of days ago I noticed one of the mollies had a cream coloured sac on its anus. Today it is still there. It is feeding ok and doesn't seem in any distress. Please can someone advise me if this is a problem and what I can do? I would really appreciate any help. Warm regards, Crescendo