Discus gills are sticking out - please help!

[peka]

Problem

1. One of my discus started hiding a lot and today I noticed that on one side her gills are sticking out from under the cover

2. She is still eating, not much. But she hides a lot, so she is not feeling well.

3. None so far. I don't know what to use

Tank/Water

4. 95 gal. 7 discus, 2 plecos. Discus from 5 years old to 2 years old.

5. 40-50% twice a week

6. Tank is about 5 years old. Planted. Substrate is gravel.

7. No

8. API water conditioner. I add it to the tank when I change water.

9. Parameters and water source;

- temp __79___

- ph ___6.8__

- ammonia reading __I don't have it on my test strip__

- nitrite reading _0___

- nitrate reading __20__

- municipal water __tap__


10. Any new fish, plants or inverts added recently. - No

11. Dried tubifex warms, Discusfood - Best Heart Flakes Super Growth, Tetrapro Color crisps, I feed 3 times a day

12. https://photos.app.goo.gl/mC3UY9YCaAtsNMBn8

[danotaylor]

High nitrates can irritate the gills. I would start by keeping your nitrates <10 before water changes. Do you vacuum your gravel substrate? Gravel traps all kinds of detritus, especially in planted tanks, increasing bacterial counts amd the chance of problems significantly.

[BrendanJ23]

As Dan mentioned, you really want your nitrates below 10. I would suggest more frequent water changes as the first line of defense/recovery and ensure your tank maintenance regime is on point (wiping glass down at least once per week, gravel vac, filter maintenance etc).

[peka]

Yes, every time I change the water I vacuum the gravel.
And nitrate level is simply not accurate. My strips have slightly pink colored nitrate marker, and it doesn't change the color after 30 sec test. So it's somewhere between 0 and 20. unfortunately I cannot give any precise number here.
Also I have 2 filters, one with built-in UV light, one with bio
Based on photos/video can you please suggest what it might be? Only one fish is affected and on one side only.

[Afgp87]

Yes, every time I change the water I vacuum the gravel.
And nitrate level is simply not accurate. My strips have slightly pink colored nitrate marker, and it doesn't change the color after 30 sec test. So it's somewhere between 0 and 20. unfortunately I cannot give any precise number here.
Also I have 2 filters, one with built-in UV light, one with bio
Based on photos/video can you please suggest what it might be? Only one fish is affected and on one side only.

I'm the right person to tell you because I'm new to the discus but i read a lot and watched a lot of videos of discus problems i think they have gill parasite and most of the people used praziquantel to treat that but do you research, i know paraguard from seachem and parasite guard from tetra have praziquantel and metronidazole, but this are banded in some countries like 🇨🇦, in that case you can research potassium permanganate treatment in this forum
they explain everything you need to do, i read pp bath they are good for flukes(is a gill parasite) you to used this i just said what I think and like I said I'm new to the discus

canisters ? And one of them you said is just the uv, you should have bio media in both you can look on YouTube pondguru he fill really nice you don't need to used his media but used something good like matrix, and also maintains don't do both at the same time, I getting really good results packing the filter like he explains