What is This??

[H]-[H]

The fish is in a hospital tank and this is the eighth day of using Erythromycin medicine..
The first three days of treatment were kinda successful with the pus all gone..
Now the bulging on its left eye has resided but still cloudy..
Its right eye however, has cleared from cloudiness but the growth is coming back?
Not sure what my next step is cause I read somewhere that Erythromycin shouldn't be used more than 10 days straight.. and I've 2 days left to treat..
From the looks of it, I don't think the growth will be going away anytime soon..
Is it safe to put the fish back in the main tank after the tenth day of treatment?

 

[H]-[H]

Hey guys, it's been a month since the fish is back in the main tank.. Although the growth are gone, his right eye is still slightly bulgy and he isn't active/eating..
Two weeks ago, I added an arowana into the tank and both fish are getting along well and the aro has good appetite as well..
This morning when I went to check on the flowerhorn, I almost flipped out when I saw a bulge on his right eye, the same spot where the growth(zit) was a few weeks back..
If I take the flowerhorn out to be medicated in the hospital tank, I'm afraid when I put him back in the main tank, the arowana might attack him and there won't be peace anymore..
I really need advice on what I should do..

Not sure if it's relevant but the flowerhorn's poop has been green and stringy ever since I put him back in the main tank..

 

[H]-[H]

I've decided not to take the risk of contaminating the arowana so I moved the flowerhorn to the hospital tank..
Now do I dose Erythromycin like last time? And maybe add aquarium salt?
I really wanted to get rid of this disease once and for all..
Please advise, thanks..