Help with my albino cory. Is it ammonia burn?

[SofieSoyy]

I noticed his right side (picture one) gill area was way redder than his left (second picture)

Ph: 7.8
Ammonia: the color was between 0ppm and 0.25 ppm (API testing kit)
Nitrite: 0ppm
Nitrate:80 ppm ( this is the very first time I've ever had that high of a reading ****)
Temp: 74°F
Gallons: 20 gallons (will be cycling a bigger tank to move fishes into)
Tank mates: 2 glo tetras, 1 common pleco (had him since he was the size of my pinky) and 1 albino cory catfish.
Decor: 3 plastic trees 1 plastic tree house and 4 moss balls. (I plan on adding drift wood and more live plants eventually)
Other info: about 3-4 days ago my filter quit working completely right after I did a water change. I got a new brand new filter that day and without thinking I threw the old filter (media and all) away. I was hoping the bacteria already established in the tank would be enough for the tank to survive without an issue.
What can I do? I love my fishy friends and I don't wanna lose em!

 

[Rick bose]

Ammonia burns usually turn black as the skin dies off. You have no ammonia so it's not that.
White stuff in the gills would not be Ich too. Not sure what it might be. Gill flukes are parasites but you'd see the gills gaping open, the fish would rub them because of the irritation too. But yeah, I wouldn't have thrown away all the old filter media right away. This is somewhat risky. I would have either some of the old filter media in the new filter or put some old filter media on the tank after running the new filter and then throw it away after a few days.


I am guessing since you mentioned artificial plants in the tank and they sometimes are quite sharp, so maybe your fish have been injured because of the plants or a common pleco in a 20g tank is obviously too much. If the pleco is big enough, it hardly gets enough room in the tank to move, so maybe its sharp fins have injured the cory. I am not sure.

Your pics are clear, so maybe someone might help to identify what that is but to me it doesn't look like ammonia burn neither your parameter can cause ammonia burn.