|
Hi Dave,
First, do not panic.
There are many things can cause fish to scratch themselves against objects. It is unlikely ick in your case since you have had your fish for over a month. Any sign of ick would have shown a long time ago.
While I can't tell you I am 100% sure since I can't see your fish, in my opinion it is 99% unrelated to parasites since you have just noticed the scratch after 5 weeks. A lot of us have quarantine tanks for new fish just came in. It is to prevent them spread possible parasites and diseases to the fish in our already established aquarium. Usually we leave the new fish in the quarantine tank for only 2 to 4 weeks, because any sign of diseases and parasites should have shown by then.
Ick or ich has a life cycle of only a few weeks. Although they might not show as white spots on the fish at first, you should have definitely see them on your fish in 5 weeks if they were there in your aquarium.
I acknowledge there are other parasites can cause fish itch and scratch against objects, it is also unlikely since it has been more than 5 weeks before you have noticed the behavior.
Second, other possible causes.
Trace of ammonia and some other chemicals in the water might cause fish to "flash" (scratch against objects). Keep water quality at excellent level can help.
Have you done the weekly partial water change? You need to replace 30 to 50% of the water once a week. In your case, you may increase the frequency and do this once a day for a few days to see if the problem goes away. A lot of problems can be fixed by better water quality. Feed your fish less food and make sure no leftover after each feeding will help the water quality too. When you do partial water changes, make sure you remove the fish waste at the bottom.
Third, do not use salt. It has very little proven benefits.
Even (if) there are parasites such as ick, to kill them with salt you will also need to reach the concentration to kill the fish. Absolutely do not jump into the conclusion of ick and use medications, meds can cause more problem and should always be used as the last option.
To treat ick there is the "heat treatment". Ick dislike warm water and most ick strains will stop reproducing at 86F+. To take advantage of this, we have successfully eradicated ick by gradually increase the water temperature to 86F over the course of many hours (to give the fish time to adopt). Keep the 86F water temperature for 2 weeks should be sufficient to let the existing ick run its course of life cycle without reproducing.(all ick died off).
Let me conclude my answer for you.
Do nothing except partial water changes and cut back on feedings to ensure the excellent water quality. in the case you start to see the white spots, share a photo with me. If it is ick, then try the heat treatment after consulting with me.
Good luck
| 
