Danio With "cotton Wool" Growth

[JustKia]

*Water parameters.
Tank size: 125L
pH: 7.6
ammonia: 0
nitrite: 0
nitrate: 20
tank temp: 25C

*A full description of the fishes symptoms.
1 Female zebra danio has a small (1-2mm) "cotton wool" like growth at the very top of her right hand side gill.
She is not skinny or bloated.
She is not rubbing or flicking.
She is eating normal, pooping normal, acting normal.
Gills are not red or swollen.
Symptoms appeared 2 days ago (Thursday), there has been no change in size of "cotton wool", no other fish are affected.

*When was last water change and how much.
Monday ~20%

*Any chemicals and treatments you add to the water.
Stress coat for dechlor.
Added pimafix on Thursday and Friday (anyone notice that fish love this stuff?)

*What tank mates are in the tank.
Stocking as per sig - yes, I know some will say fish are not compatible, but it works for the particular fish I have =)

*Finally Have you recently added any new fish?
No, newest addition was a peppered cory born (or rather hatched) in the tank a few weeks ago.

*Exposure to chemicals:
None, except stress coat and pimafix.
Tank is covered, not open - open tank = deli bar for kitties

*Other
Regular lights are on from 7.30am-10.15am and 6.00pm-8.00pm
Moonlights are on from 8.00pm-10.00pm
Lots of plants

I have pimafix, melafix, anti internal bacteria and anti fungus & finrot meds.

 

[WILDER]

Cotton wool growths are columnaris. You need to add some myxazin by waterlife to the tank with the pimafix.
You could use the anti internal bacteria med by interpet with the pimafix.
The anti fungus and finrot med not that great on columnaris.

 

[JustKia]

Thanks Wilder,
I don't have myxazin, so will have to order it (at least I'll have some on hand then should I ever need it)
I've done a ~25% water change and added a dose of anti internal bac med, and will add second dose as directed on day 4.
Keeping close eye on tank, "cotton wool" hasn't gotten any bigger or spread anywhere else so that's good (I think).
Affected fish is still acting, eating, pooping normal.

 

[WILDER]

You can double dose the anti internal bacteria med in severe cases. But it might knock your water stats.
If no improvement much by the 4th day when you add the second dose I would maybe think of doubling it.

 

[JustKia]

Is double dose safe with corys and kuhlis, plus I have juvie corys in there too - and my peppereds just spawned again, and the danios are doing so too.

 

[WILDER]

If there coped with the single dose they should be fine.
I have doubled dosed in the past with corys and they were fine.

 

[JustKia]

I gave the second dose yesterday.
I wasn't brave enough to double dose. But the "cotton wool" is all but gone. There's just a tiny tiny bit of white (like a fleck of dandruff) if you look really close.
Hopefully, the second dose will shift that.
I'll do a big water change on Saturday and see where it's at then.
Good news is that the fish still looks otherwise healthy, all the fish look healthy and none have shown any signs of "cotton wool".

Wilder, thank you, once again your knowledge and kindness in sharing that knowledge is very much appreciated.

 

[WILDER]

Glad the fish are nearly back to full health.
Well Done.