Neon Tetra Concerns - NTD and Finrot, maybe?

Hi friends,

Tank
What is the water volume of the tank? 50 Gallons (not currently full so about 45 Gallons)
How long has the tank been running? Since December
Does it have a filter? Yes
Does it have a heater? Yes
What is the water temperature? 26 Degrees Celsius
What is the entire stocking of this tank? 5 Neon Tetras, 2 Dwarf Loaches, 20 Guppies

Maintenance
How often do you change the water? Weekly
How much of the water do you change? 25-30%
What do you use to treat your water? API Water Conditioner
Do you vacuum the substrate or just the water? Substrate, no more than half the tank each time

Parameters
Did you cycle your tank before adding fish? Yes
What do you use to test the water? API Full Test Kit and API Test Strips
Ammonia:0
Nitrite: 0
Nitrate: 10
pH: 7.4

Feeding
How often do you feed your fish? Once daily, extra dose on the weekend
How much do you feed your fish? Pinch of Hikari Micro Pellets
What brand of food do you feed your fish? Hikari
Do you feed frozen? No
Do you feed freeze-dried foods? No

Illness & Symptoms
How long have you had this fish? These two NT's since December
How long ago did you first notice these symptoms? 1 week ago
In a few words, can you explain the symptoms? Neon #1 is in a quarantine tank. There's a growth to the left of his mouth and what I believe to be white discolouring on the side. I believe this is NT Disease and he'll need to be euthanised. The second Neon #2 has what I suspect to be finrot. Both swimming around/eating just fine.
Have you started any treatment for the illness? Moved NT #1 into a quarantine tank (5 Gallons)
Was your fish physically ill or injured upon purchase? No, looked heathy
How has its behavior and appearance changed, if at all? Nil behaviour changes

Explain your emergency situation in detail.
We established the tank (Dec 2) and didn't add the tetras until Dec 29. We added the loaches along with the guppies at the same time, towards end of January. Tank best described as otherwise thriving (tetras happy/playful, loaches playful, guppies had fry so we've whittled the 60 we ended up with down to about 20. Random deaths over the past 6 weeks - once Tetra just died randomly, and all adult guppies died about a week after releasing fry.

Neon #1 had a lumpy growth out of the mouth which the fish store suggested may be cotton mouth. Currently on a treatment of Acriflavine and Aquarium salt.
Neon #2 overnight had fin rot as per pictures. This is in the main tank - a half dose of aquarium salt was added.

So my questions

1. Should Neon #1 be euthanised if he has NTD?
2. What's the best way to deal with fin rot? Continue water changes?
3. Other thoughts?

 

Yes water changes and lowering stress. Guppies are not hardy enough these days. Neon tetras aew fragile need softer water. They make peat packs you can add to water to soften it.

 

1. Should Neon #1 be euthanised if he has NTD?
I would not euthanise a fish that is eating and otherwise behaving normally. It is highly unlikely to have Neon Tetra Disease as Neon Tetras suffer from Columnaris not NTD. There is a good chance of recovery if suitable conditions are provided though it sometimes takes a month or two.

2. What's the best way to deal with fin rot? Continue water changes?
The fin rot is caused by the Columnaris bacterium which lives on the fish skin and does not normally cause a problem unless the fish suffers from stress (particularly from transport between aquaria and different water conditions). Stress leads to the immune system, which usually controls the bacterial population, being compromised. Good environmental conditions and absence of stress can see it reversed without resort to medication. Provide well oxygenated water, plant cover for security, absence of bullying from tankmates, suitable temperature, quality foods and of course good "parameters" which you have.

3. Other thoughts?
The Columnaris encountered is more virulent than wild types due to the nature of fish farming. Old Neon Tetras in particular can suffer from Columnaris on the gills which can lead to rapid gill movement and can shorten their life. Loaches (species?) may belong in larger groups than pairs. 26C is too high for Neon Tetra long term I suggest 20-24C but this may not suit loaches. Neons can be aggressive at high temperatures as this promotes breeding season behaviour.

 

Dwarf loaches for the pair (species). Want to get more but wanted the random issues to tidy up first.

Tank back down to 24 degrees as we enter the winter months with the heater. So, treat the columaris with salt or should I medicate?

 

You could consider adding cattapa leaves. I can't bring up the research done with them but supposedly it is used in tilapia farming since the fish experience a lot of stress in the environment which of course leads to a weakened immune system. It is super cheap and I observed that it really helps. I had a betta with a tumor at one point which I assumed might have been an abrasion and I just added it in and the swelling reduced two days after.