Please don't use Melafix or Pimafix. Those products are nearly worthless. Amazing how they've taken over the industry...
Akskirmish is right, simply ramp up the water changes and increase the salinity level of the tank. If after a few days of that nothing improves, move to the medicine (actual medicine!) route.
Next question....... How long do you expect an umbee to survive in the tank with a pair of dovii? I hate to be negative, but this situation won't end well unless you make some changes. It sounds like you've moved the umbee (correct?).
Akskirmish is right, simply ramp up the water changes and increase the salinity level of the tank. If after a few days of that nothing improves, move to the medicine (actual medicine!) route.
Next question....... How long do you expect an umbee to survive in the tank with a pair of dovii? I hate to be negative, but this situation won't end well unless you make some changes. It sounds like you've moved the umbee (correct?).