What is wrong with my tang?

Have had this tang since adopting the aquarium over a year ago. He came with the tank. He had already had fin rot in the past and has not had proper fins since we adopted him. From time to time he would have red spots appear on his body but now the red areas are turning white and look raised.

We have a UV filter in the system and cleaner shrimp - but could this be parasites?

 

Head and lateral line erosion disease? (HLLE)

 

Sure looks like HLLE and possibly other things going on..It also appears to be suffering from malnutrition .

 

What do we need to feed to prevent this? We offer brine shrimp, nori and a frozen formula cube regularly. Thought that might be enough variety.
We love this fish and would like to do what we can to help him.
So far he is eating well and swimming around actively.

 

Stop feeding brine ,it has no nutritional value to the tang(or any fish really).HLLE is most often related to poor diet(but is actually still a complete mystery)..Tangs are mainly herbivores .Yes they will eat meaty foods but that doesn't make them omnivores ..they need greens ..The nori is good ,but also get broccoli ,spinach ,formula 2 (flake or pellets) ,hikari marine A and some spirulina for it..Vita chem is good to soak the pellet foods in and it will also help the HLLE..
Water is pretty key too..Keep it pristine and the tang will recover in time .

 

[QUOTE="FeedYourMachine, post: 1555952, member: 36281"]Stop feeding brine ,it has no nutritional value to the tang(or any fish really).HLLE is most often related to poor diet(but is actually still a complete mystery)..Tangs are mainly herbivores .Yes they will eat meaty foods but that doesn't make them omnivores ..they need greens ..The nori is good ,but also get broccoli ,spinach ,formula 2 (flake or pellets) ,hikari marine A and some spirulina for it..Vita chem is good to soak the pellet foods in and it will also help the HLLE..
Water is pretty key too..Keep it pristine and the tang will recover in time .[/QUOTE]


This is not really the case.Enriched brine shrimp does have nutritional value..It really depends on the foods they are raised on.
Brine shrimp will ingest any food appropriately sized for their digestive system at time of feeding.
Over the years, people have used many foods in raising them.
The quality of food fed to the brine shrimp is directly affecting the quality of the brine you feed to whatever you are feeding it to.

 

Can you tell us more about your tank? Size, test results, inhabitants, equipment, etc.

 

It's a 90 Gallon system with 100lbs of live rock, a sump with refugium, bubble magus protein skimmer.
We have the tang, a flame angel, diamond back goby, two clown fish and a black Combtooth blenny. There are 3 cleaner shrimp, a few emerald crabs (they seem to be multiplying - have seen at least one baby in the rocks) and snails. We have a few LPS corals and some mushrooms.
I tested the water last night:
PH was low, 7.8 or so.
Dkh 9
Calcium 450
I had tested nitrates and phosphate last Sunday:
Nitrate 2ppm
Phos 0.04
Salinity 1.026
Temp 78-79
I'm pretty new to testing the tank parameters (had relied on water changes in the past.)
We had a recent problem when we were traveling for 5 months. We hired a "professional" to do water changes twice a month but came home to a horrible mess. Green hair algae everywhere and filthy water. On another thread I was told I have been too aggressive is restoring the water quality, that I should be taking it slower to prevent shocking the system. So that could be a factor.
Sorry if this is TMI.
I openly admit to being a novice and making mistakes due to ignorance.
Thank you for your help.

 

Sounds like you are doing the right thing trying to get some guidance. From what little I know of HLLE, of it is HLLE, the water quality should be restored asap or the fish moved to a clean tank. Here is an article you can look at. Try to see if the symptoms look the same. There are other diseases that are similar.

http://www.coralmagazine-us.com/content/activated-carbon-hlle-smoking-gun-found

 

Not TMI at all, and we're all newbies at building oceans. I'd like more detail on what you feed and how much/how often.

That said, my initial thoughts include losing any carbon as billme points out, getting a grounding probe, and feeding more - particularly more nori. If any of this drives up nutrients, you could look into improved nutrient control, like carbon dosing, bio pellets, or GFO.