Yellow Tang, ich? Fungal? Not sure...

I have a juvenile yellow tang that I just recently added to my tank. I don't have a qt, because I don't have a job and I'm still pretty new to the hobby. I've had ich before, so I know what it looks like, and this looks exactly like ich, but he's had it for about a week and a half and it shows up at night, but its not there in the morning. It also hasn't showed up on any of my other fish in the past couple weeks. He swims around, he's very playful still, he is a very healthy eater (diet consists of brine shrimp and garlic soaked green algae strips with the occasional hair algae in the tank). Is this possibly a stress-caused disease? I'll post pics as soon as I figure out, but it really looks like nothing more than ich with a little loss of color.

 

My params are:
8.0 ph
Very low nitrates, just above 0
Nitrites 0
Ammonia 0

 

And now my lionfish is swimming upside down and hanging out at the top of my tank. He also has a cloudy eye, and it looks like he has ick as well...

 

What sized tank?

Ich (Crypto) looks like salt specks present on the fish body. It is almost always stress related, and tangs are notorious for getting this, especially on tank moves (addition to a tank)

Fungal would present typically in a white patchy area, often it looks fuzzy, like a patch of cotton on the flesh. You would not see this come and go in all likelihood.

A pic would help significantly in assisting you further.

 

It's a 75 gal, and it's a small tang, so he has enough room to swim around. And I know it's ich, but it hasn't spread to any other fish, so is it only stress

 

How long has the tank been running?

 

Its not the yellow tangs night colors (camouflage) your talking about is it? I ask because your saying it only happens at night and is not there in the morning.