Silverish discoloration on hippo tang

[Sablah]

I noticed this discoloration on the tangs head tonight when the lights were off. When the lights are on, its not really noticeable. It normally sleeps in the rock at night, so I didn't notice it before. I happened to try feeding mysis shrimp tonight and it came out to eat it, which is why I was able to see it. I recently purchased this aquarium already setup and established, so I'm not sure if this was always there or not. Any idea what it might be?

 

[Ron Reefman]

Some/many fish change coloration at night. Some only change a little bit, some change quite dramatically. I wouldn't worry about it if it looks normal during the day.

 

[Wen]

Hard to see but does it look like HLLE...?

I’d make sure it’s getting a varied diet and vitamin soaked nori daily.

 

[Big G]

HLLE Here's pictures for you to compare to your fish and with treatment plans:

HLLE (Head & Lateral Line Erosion)

Head & Lateral Line Erosion "HLLE": Symptoms - HLLE literally looks as though the skin is rotting or peeling off the fish. Affected areas usually include the face and lateral line, and may be white in color. Treatment options - This is more of a condition than an actual disease. Since no one...

www.reef2reef.com

 

[Sablah]

Looking at the tang during the day, when there are mostly blues on the area does look slightly discolored, but I just assumed it was discolored due to the lights. I had been running mostly all blues until a couple days ago I started increasing white (had an issue with the lights) so that's why I probably never noticed it before. I'm pretty sure it has gotten much worse in the past couple weeks. For how much time I spend looking at this tank, I should have caught this a while ago

I looked through the pinned thread about common diseases before I posted last night and I was thinking HLLE as well.

I tested for stray voltage last night and there's ~15v in the tank, caused by the heaters and pumps. Oddly enough, the Gyres someone how reduce stray voltage, as without the gyres its more around 20-22v. I don't have a ground probe and a GFCI outlet is being installed this weekend. I can order a grounding probe, though I don't know if that's needed as most people are saying that anything less than 40v-50v is normal.

I haven't used any medications in the tank except for one treatment of Red Slime Remover over a week ago, and Seachem Marine Buffer every couple days for the past week (my ph dipped after using the slime remover, so I was using this to try and keep PH levels up).

I have a two stage GFO/Carbon reactor running BRS ROX 0.8 Carbon and BRS GFO. I can stop using the carbon, though I am using high quality carbon so I'm not usre if that would make a difference.

I feed 1 cube of Emerald Entree and 1/4-1/2 cube of brine shrimp, along with a 2" x 3" piece of nori. The tang is around 5"-6". Should I be feeding more nori?

I'm going to go out today and get vitamins. How long do I soak the nori for? Should I get multiple types of vitamins and soak all at once?

The tang does not like to swim still for the camera :/

Livestock:

Hippo Tang
Chromis
Clownfish
2x Pajama Cardinals
Eiblii Angel
Diamond Watchman Goby
3x Emerald Crabs
2x Sand sifting stars
Brittle Star
Serpent Star
Fire Shrimp
Scarlet Skunk shrimp
Red Banded Coral shrimp

Two types of GSP and some kind of mushrooms (not sure)

Params:

PH: ~8.1
Alkalinity: 7.6dkh
Phosphate: ~0
Calcium: 420-440
Temp: 77-77.5
Nitrite: ~0
Nitrate: <5ppm
Ammonia: <0.1
Magnesium: 1140
Salinity: 33ppt

Tank is 120g.