Start hauling rocks and preferably use a divider. Dartfish are a monumental pain to catch.
...and are infinitely more difficult to catch in the wild.
From white spots? why not use herbatana should work if eating.
Going to stress fish out when trying to catch. Best would be to get fish trap or be prepared to rearrange, Probably the worse. Good luck
I have no scientific proof if it works or not but it has helped me in the pass. All i know is it strengthens immune system so that fish can overcome disease by fighting it off but not remove it from tank.
It allegedly improves their immune systems. But so does improved water conditions, improved feeding, and a host of other variables. I recently transferred a bunch of fish to another tank which caused stress and a whitespot outbreak in my surgeon (as expected). Now that it's settled into the new system the stress has diminished and the whitespot has gone (not completely gone from the system of course, but it's in check).