Black Noses On Newish Fish

[2excitedkids]

Please could you advise me.

I have had 4 denisons barbs for 8 days. They are active,swimming and eating though do tend to swim right at he bottom of the tank.
They have red noses and when I looked at 3 of them tonight they noses seem to be more black in colour and not much red showing ( a bit like they have smudged their nose in charcoal).It is only their noses.
Their red stripes are still red and the other one still has a red nose. They aren't rubbing or flicking and their gills look normal.
Is this a sign of disease or do their noses change colour?? As I haven't had them long I don't know. The other fish are fine.

Tank stats
260litre planted juwel vision
Ammonia 0
Nitrite 0
Nitrate 25 as is tap water.
ph 7.5

Water change twice weely 20% - last yesterday morning.Filter rinse weekly.
Only add dechlorinater and flora boost.

Other inhabitants 4 platys (and one tiny platy fry), 2 mollies, 2 albino corydoras, 1 pitbull plec.
Tank 1 month old (took mature media from previous tank).

I can't get a photo as no digital camera as yet.

Is this normal and just my imagination or could this be the signs of a disease.
Very worried about them so advice greatly appreciated!!

 

[WILDER]

Black mouths can be due to digging in cichlids.
I wouldn't worry to much yet.
Have you had ammonia reading recently.

 

[2excitedkids]

Black mouths can be due to digging in cichlids.
I wouldn't worry to much yet.
Have you had ammonia reading recently.

I'm so glad its you wilder!
We have been checking every day since we got them as we were worried we may get a mini cycle. We have had no ammonia and a very slight trace pink in nitrite (api )few days after got them but no where near the 0.1 mark

Am so inexperienced I don't really know what is and what is not ok...I think I worry too much but would hate for them to be ill and do nothing! They do a bit of digging as they aren't keen on the flakes and prefer the catfish pellets and blod worm but we have the finest gravel avaliable due to having the corys.

 

[WILDER]

I would just keep an eye on them.
Black patches can be ammonia burns that are healing.
If there mouth were white and fluffy then I would worry.
Take a look under black patches.
http/www.fish-disease.net/diseases.htm

 

[2excitedkids]

I would just keep an eye on them.
Black patches can be ammonia burns that are healing.
If there mouth were white and fluffy then I would worry.
Take a look under black patches.
[URL="http/www.fish-disease.net/diseases.htm"]http/www.fish-disease.net/diseases.htm[/URL]

Thankyou, possibly was something that happened in lfs and now healing??. Hopefully nothing else will occur, will keep my fingers crossed.

 

[WILDER]

You could check in the barb section as I have never kept them.
All I can think of it being normal, or ammonia, burns or digging.