API general cure

So I have 2 sick discuss. One blue now very very black! Other white and red stripe. The red stripe has been perfect from day one and still is! Just always hung out opposite side of tank. no insterest in food.
The once blue fish eat really good. I have aways done a 75% water change using one day aged water and prime. Bare bottom tank cleaned poop constantly (case it's bare) VA one 5 gal bucket! 90 gal tank.

I bought them both September 8th along with 2 other ones that are doing excellent! With my other 3 discuss!

I have had them now in a hospital tank 10gal. Temp is 89 for 6 days using one package of API gereral cure with all in one remedy by marinland. 2 tabs a day. Yesterday I added ebson salts so 2 days of 2 tablespoon each day. Also raised temp to 91 today ( gradually doing)

I did a 50% water change daily on the hospital tank
This tank uses a small Cascade 300 filter.

I didn't remove the carbon from it. I did today and cleaning the filter.

I purchased a bundle seachem kit...focus, kanaplex, metroplex.

I have one gereral cure packet left. What should I do? Please help.

Do you see any odd (Hex looking )feces on the bottom of the tank or their feces is brown and normal ?

Keep dosing General cure (Metronidazole) for a few more days before you rule it out.
Is the filter in your QT cycled ? Keep an eye on the water quality there since 10 Gall. Is a small volume for 2 grown discus on high temps and metro . Maybe up the daily changes to 100% there .

Never saw any poop. After the 5 day of API general cure I started to use seachem metro Plex and kana one scoop each with 60 percent water change everyday! And rasied temp to 92. 5 day they have been on the merto Plex and Kano and now the red stripe fish is eating great! Blue died. He has been eating great for 2 days now. Eating for the 1st time in 30 days! And he never looked bad so I found this strange never looked thin. New important question.. tank temp is now 90.5. I lowered it yesterday. I will lower a bit tonight. Main tank is always 84.7-85.5. when do I stop treating the fish? When should I put him back it the main tank? Do I lower the temp more then 1 degree a day? Thank

Sorry for your loss Lewjo .

I ussualy treat with Metro for full 14 days and never less than 10 days .
Api general cure and Seachem Metroplex is basicly the same stuff - Metronidazole .
So aim for at least 10 days treat from your start with Api to the end of treatment with Metroplex.

Leave the fish for at least one week in your QT tank after it regained its appetite back .

Gradually lower the temp by 1 C degree daily in the QT tank to get him adjusted to 84 F degree for the transfer in the main tank .

Thanks will do! Seems like I stop the treatment day after tomorrow! And I'll start lowering temp. Fish is eating well now