Can 2 dots of ich appear and disappear within hours?

[hails]

So I didn’t do full quarantine on a tang about 4 months ago, introducing ich to my dt lesson learnt and I pulled all the fish into a hospital tank and treated with cupramine. During treatment the tang died but everyone else made it. Then I cleaned the sponges too much and had nitrite spike so took the fish back to my lfs and cycled the tank again. I then went back to the lfs and picked up three of the fish - a foxface and two clowns. I then put them back in the qt and treated them again for 30 days. This whole process took 110 days during which the display has been fallow. Three days ago I finally put the fish back in the dt (hooray!)
The next day I saw two white spots on the foxface so I caught them again that night and put them back into qt . Went to bed feeling gutted and next day the spots were gone..??
There are still low levels of copper in the qt so could that of made the spots drop off instantly?
The only explanation for the spots is that I must of let the levels drop below therapeutic at some stage? Although I tested all the time and always dosed the wc water before I replace it. Or maybe I’m colour blind ? Was using salifert test.
Have a Hanna copper checker on order that should arrive next week and I will redo the whole dang process, but my question is just whether it is 100% ich? Could it appear as 2 dots and then disappear within hours? He looks fine now, is eating like a pig and is his same old self. I am fully prepared to do the treatment/ fallow all over again, but just want to make sure I’m not wasting my time if it could be something else...
Sorry for super long post

 

[Jay Hemdal]

Not all white spots are ich, sometimes they are just dust motes. However, ich trophonts grow in size and then drop off in a day to 36 hours, and the time that they are clearly visible can be pretty short. it’s pretty common to see the spots come and go in the first few days of an infection. I would just watch the fish for now.
Jay

 

[hails]

Not all white spots are ich, sometimes they are just dust motes. However, ich trophonts grow in size and then drop off in a day to 36 hours, and the time that they are clearly visible can be pretty short. it’s pretty common to see the spots come and go in the first few days of an infection. I would just watch the fish for now.
Jay

Thanks for the reply, do you know if more spots will appear if he is in low levels of copper? Or will it suppress them. should I try take all of it out and watch him for a bit?

 

[Jay Hemdal]

Thanks for the reply, do you know if more spots will appear if he is in low levels of copper? Or will it suppress them. should I try take all of it out and watch him for a bit?

Low levels of copper typically do not "work partially", more typically, less than a full dose of copper allows the ich to continue on. Copper is really an "all or nothing" medication.

Jay