High nitrites could be damaging her gills. I would add salt to the water that seems to block at some extent the nitrite from the gills. And I also agree a parasite. I would use metro and make sure she ingests it somehow. Inject it in something she is still eating.
Prazi is great for external, but metro I feel would be better for internal.
Is that a typo? Did you mean nitrates are 10ppm lowest, not nitrites?
As already pointed out, it's quite possible the fish have internal worms/parasites. It's probably from the raw fish food.
Prazi pro treats only tape worms and not round worms, so it is not a very comprehensive treatment but one doesn't know what the fish has until its treated...Good luck.
Sorry ment nitrate not nitrites got autocorrected and confused
Action taken today has been:
No feeding
80% water change to ensure prestine water
Discussion with Vet with fish background
1/2 of recommend does of prazi
1/2 to be added in 3 hours
Does is 1 gram of praziquantel powder per 400ltr of Aquarim water
Plan is 5 days of prazi no water changes, minimal feeding, at least 50% water change leave tank for 2 days
80% water change new prazi dose for 5 days
50% water change
Leave tank for 2 days
80% water change
Dose tank with prazi 3rd and final time
5 days 50% water change
Then ideally back to normal
After 3 days if I have not seen any improvement, vets says I must take threw a poop sample to be analyzed to make sure we are treating correctly.
Advise and feed back would be greatly appreciated
And thank you for help thus far