Silver Arowana / ID Shark = Bad Skin Patches (both over 2')

Both are in my 1,000 Intex Pond. My params are not an issue. This is an established pond 2 years old.

I just left for an overnight trip out of town and when I got back. This is what I saw. Don't think there's an issue with the water as all the other fish look/swim/eat normal. There's one photo of the silver beside another silver.








Please tell me what you guys suspect it is. The last two photos were taken 12 hours after the first few shots.

I did an 80% water change yesterday. This morning, they look a bit better. Any idea what this is and what I should do to prevent this from happening?

Thanks for the reply. After I did an 80% WC, the white spot on the ID Shark went away in a snap, like within minutes, crazy. Never saw something like that go away so fast. He is now back to his old piggy self.

The aro also got back his appetite, but the dark spots are still there, will see after a week if it doesn't go away, then might want to treat him with salt.

Thanks for the reply though, appreciate it.

After I did a big WC, the ID shark's marks got erased, as in almost instantly, the silver looks the same but his appetite is insatiable, am actually trying to avoid feeding it, but it's very hard.

Sure hope it's not Red Spot.