Fry illness?

[Synirr]

Yesterday I noticed that about 5 fry in my fry tank had a white spot on their tiiiny little caudal fins. On some of them it's a bump, and on others it's just a spot... it looks like ich, but there's no way that's possible. The last ich outbreak I had was months ago, it has now been completely eradicated, and anything that came into contact with the contaminated tank was thrown away and never used on any of the other tanks after that.
There's only one spot per fry and it's on their caudal fins only. They seem perfectly healthy and happy aside from that... swimming around fine and eating like hogs. Any idea what it could be? I separated all the fry with the spots into a bowl by themselves just incase

 

[wuvmybetta]

Ich is always, always in fish water. It only attacks when the fish become stressed. With fry it could be anything that stressed them out.
Could it possibly be velvet? I've had that on fry a few times but it cleared up in just a few days with maracide, silver and bettamax.

I suggest taking a flashlight to them and getting to the root of the problem asap. If it looks like gold dust, it's velvet. Betta fry get it at the drop of a hat. Good luck!!

 

[Synirr]

Well, I flashlighted them and don't see anything... this is really weird

I did a water change yesterday or the day before and that might have stressed them out a bit I suppose.
Each fry only has one spot, it's only on their caudal, and it hasn't spread since yesterday... still only the same 5 fry. I guess I'll just wait a day or two and keep a very close eye on them.

Edit: Are you sure ich is always in fish water? That's what I've heard too, but to be honest, I'm very skeptical. I've never had a fish get ich out of the clear blue, even when they have been weak or stressed... they get bacterial infections and whatnot, but never ich. It seems like all the processing water goes through at the water treatment center would kill something like ich with relative ease

Edit again: I take it back, the white spots aren't bumps on any of the fry like I originally thought. It must have just been a trick of the light when I was looking at them earlier, but now that I look at them very closely from above, it's clear that the spots aren't little nodules like with ich. Still no clue what it could be, though.

 

[Synirr]

Well, the 5 quarantined fry are still going strong today and look the exact same. None of the others have developed any white spots either. I'm really just absolutely stumped on this one. Anybody have any ideas? I'm beginning to think it's nothing at all... just some weird colouration or something

 

[OrkyBetta]

Maybe just coloring, or some sort of fin problem?

 

[Synirr]

Maybe just coloring, or some sort of fin problem?

Yeah, I was thinking maybe they were staring to get finrot but it doesn't seem likely.. their tiny little caudals are still perfectly intact