Tetra white nose?

Hi all. This is my first post. I am new to fish keeping and i have had my tank since august this year. I started it by cycling it with tetra safe start and with 3 platys and 5 neon tetras. and building with a few fish every few weeks / month I now have 4 tetras (one disappeared a month ago never to be found), 4 harlequins, 2 platys, 6 guppys and 3 panda corys.

Only today i noticed one of my tetras has a white dint that looks like the top of his nose has been taken over by this white spot. He is still eating and swimming with the other 3.

My water parameters (using dip sticks) are ammonia less than 0.5, gh 60, kh 40, ph 7, no2 0, no3 20. I do 15-25% water changes weekly.

If anyone can help id be grateful. All my other fish of all species seem fine and healthy

I’m curious if anyone has an answer to this post. I have one tetra with the exact same issue. The pic is identical to my fish.

It's either mouth fungus (Columnaris) or a fat lip from swimming into something and bruising the mouth.

How long has the tank been set up for?
Have you tested the water for ammonia, nitrite, nitrate & pH?

How long have you had the fish?
How long has the fish had the white bit on its mouth for?
Have you added anything new to the tank in the last 2 weeks?

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If it's swelling from a fat lip it will heal up by itself over the next few weeks. But if it's Columnaris, it will kill everything very quickly.

Colunmaris needs to be treated with anti-biotics. However, these will wipe out the filter bacteria so you need to monitor the ammonia and nitrite levels during treatment and for the month after treatment. If you get any ammonia or nitrite readings, do a 75% water change and gravel clean the substrate each day until the readings are 0.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

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To work out the volume of water in the tank:
measure length x width x height in cm.
divide by 1000.
= volume in litres.
When you measure the height, measure from the top of the substrate to the top of the water level.

There is a calculator/ converter in the "How To Tips" at the top of this page that will let you convert litres to gallons if you need it.

Remove carbon from the filter before treating or it will absorb the medication and stop it working.

Before treating, wipe the inside of the glass down with a clean fish sponge. Do a 75% water change and gravel clean the substrate.

Clean the filter if it hasn't been done in the last 2 weeks.

Increase surface turbulence/ aeration when using medications because they reduce the dissolved oxygen in the water.

So the spot is above its lip, almost directly over where one nostril would be. This tank is 9 gallons and has been active for 5 months with no issues. I test with Marineland 5-way fresh water strips and everything appears to be in the “safe” ranges.

I’ve had these tetras for 6 months (started out in a different tank), and only one has the spot. I just noticed it this evening and I look at the tank frequently throughout the day. It’s on our dining table so I stare at them when we eat and I always watch them when I feed them so I know this is a brand new issue.

I also have a betta and two spotted catfish in the tank and none of them seem to have any spots anywhere.

Nothing new has been added in the past 3 months. I did just clean the tank (25% water change), pump and filter two days ago though.

Do a 75% water change and gravel clean the substrate every day for a week. If it's a bacterial infection, the big daily water changes and gravel cleaning will dilute the number of disease organisms in the water and reduce the chance of the other fish getting it.

Monitor the fish over the next 24 hours. If it gets worse then treat it immediately. Columnaris spreads very quickly and kills 99% of fish infected with it.

If it doesn't get worse over a couple of days, then it's probably a fat lip and should clear up in a week or so without any medication.

Will do! Thank you.