Is This A Fungus On My Betta's Tail?

HI Everyone! About 15 minutes ago I noticed this white fuzzy clump on the end of my Betta's tail. I managed to get a close up video of it.
Is this a fungus? If so, how would I go about treating this? Should I set up a small 3 litre hospital tank? Will the fungus infect the 20 Litre tank he is in right now?

This is the medication I have on hand:
-Tri-Sulpha tablets (which claim to aid in the control of white spot, body fungus and tail rot).
-Fungus and finrot cure with malachite green
-Betta Fix
-Aquarium Salt.

20L Tank Parameters:
Temperature: 24-25 Celcius
Ammonia: 0-0.25ppm (the ammonia is there probably because I did a water change yesterday and there is ammonia in my tap water)
Nitrite:0
Nitrate:0
The tank was cycled completely before I put him, before I had some guppies in the tank.

 

Looks fungus-Y to me.

Fungus and finrot cure with malachite green

Is this API Fungus Clear or API Fin & Body Cure or something else?
I'm leaning towards that because I think it has a better chance of treating both fungus and bacteria die to the malachite green.

Do you use Prime or other conditioner, preferably one that detoxifies ammonia? Each time you water change, you could be risking ammonia burn or damage, etc.

 

Looks fungus-Y to me.

Is this API Fungus Clear or API Fin & Body Cure or something else?
I'm leaning towards that because I think it has a better chance of treating both fungus and bacteria die to the malachite green.

Do you use Prime or other conditioner, preferably one that detoxifies ammonia? Each time you water change, you could be risking ammonia burn or damage, etc.

It's an Australian brand called PETS. I use either Prime or API Ammo-Lock to detoxify the ammonia, definitely don't want to risk burns!

Should I do the treatment in the 3L?

 

Hm. Then I'm kinda concerned because if you have ammonia now and you water changed 2 days ago, the ammonia should have been converted to nitrates by now in a properly functioning system. What's your pH?

It's an Australian brand called PETS

Well, that's a terrible brand name. I looked up "PETS fungus and finrot cure" and got generic results about pets with fungus and basic finrot treatments.
Could it be Interpet brand?

Should I do the treatment in the 3L?

I have to keep doing conversions. That seems to be a little less than a gallon... That may be difficult to dose. I'm not sure if your meds dose per liter?


Ah-ha! I found this! Aquarium Fungus and Fin Rot Cure is that what you have? I just wanted product information and an ingredients list but can't find it.
Edit: nevermind, there's a MSDS PDF. It has Acriflavine, a "topical antiseptic," according to Wikipedia. Combined with malachite green, I think this would be a good start to treat with.

 

Hm. Then I'm kinda concerned because if you have ammonia now and you water changed 2 days ago, the ammonia should have been converted to nitrates by now in a properly functioning system. What's your pH?


Well, that's a terrible brand name. I looked up "PETS fungus and finrot cure" and got generic results about pets with fungus and basic finrot treatments.
Could it be Interpet brand?


I have to keep doing conversions. That seems to be a little less than a gallon... That may be difficult to dose. I'm not sure if your meds dose per liter?


Ah-ha! I found this! Aquarium Fungus and Fin Rot Cure is that what you have? I just wanted product information and an ingredients list but can't find it.
Edit: nevermind, there's a MSDS PDF. It has Acriflavine, a "topical antiseptic," according to Wikipedia. Combined with malachite green, I think this would be a good start to treat with.

Haha yes it is a stupid name, very generic! You found product, it isn't exactly an aesthetically pleasing website but oh well. The instructions use say use 5mL per 20L, so I just calculated how much for 3L from there. He is in the 3L tank now with malachite green next to my bed so I can watch his progress. Thanks for your help, will keep you updated.
Edit: My pH is around 7.6
I will probably add some seachem stability

 

CheshireKat He just died There was fuzzy stuff all over the bottom of the tank as well during the period of time in which I medicated him.

 

CheshireKat He just died There was fuzzy stuff all over the bottom of the tank as well during the period of time in which I medicated him.

Oh no! I'm sorry. That's kinda of strange that he died. Maybe it was worse than it seemed? Or spread to his gills or something? Who knows. And to have it all over the tank as well? Huh. Do you think it fell off him or grew separately?

 

CheshireKat He just died There was fuzzy stuff all over the bottom of the tank as well during the period of time in which I medicated him.

I'm very sorry for your loss.