need help

  • We are currently upgrading MFK. thanks! -neo
what kind of fish?

Post of some water specs

it's hard to diagnose with this little information, but could be anything from internal parasites to malawi bloat. I'm not going to suggest any treatments without knowing what kind of fish because some fish don't take certain medications very well
 
Your case is most certainly internal parasites. Search for metronidazole, praziquantel or levamisole hydrochloride. The last one can cover more parasites than the first two.
 
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