What is wrong with my tang?

We give one cube of brine shrimp, one formula 2 cube and a piece of nori (maybe 2x2 inches roughly) daily. The snails and crabs also like the nori.
I started nopox a few weeks ago due to the persistent algae problem. So far it has done a great job, along with water changes every other week.
The only carbon I have is in a bag in the sump. I thought this would help remove contaminants and toxic stuff the corals excrete. Is it better to be without it?

 

Heres my old purple tang ..I bought him when he was roughly 6 years old ..After about 6 months my system he started to develop HLLE,,I tried it all..Grounding probes,no more carbon doubled up on WC's ... It wasn't until i changed the food i was feeding(this was one of my first fish several years ago,and wasn't feeding it properly) and started adding Vita-chem that it cleared up ..While others may have removed carbon and it cleared up,and someone else installed a grounding probe and that cleared it up.
The truth is HLLE is simply caused by fish being in our tanks and not the oceans.I don't believe there was ever a case of HLLE seen on fish in the ocean.We can only try our best to give them the best environments possible.

 

FYM makes a good point. There is some anecdotal evidence that vitamin C can help.

 

I agree with what's been said. I'll add my thoughts.

I think your water quality is the issue. You have an algae problem being suppressed. That means your nutrient numbers are questionable. You need to fix the water quality issues along with the rest of the good advice here.

My recommendation is carbon dosing, because it's easy for a careful newbie to implement. Others may have other suggestions and there are many ways to accomplish the goal. Stick diligently to the one you chose.

I'd also get rid of the activated carbon bag. I happen to use it, but if I saw evidence of HLE, I'd yank it. I've never tried it, but that Chrmipure Blu may be a good alternative. Someone who knows more about it could chime in.

 

Thanks to all for the responses. I have started a vitamin C supplement and have been using Red Sea Nopox for a few weeks. It has brought the nitrates down a lot. Phosphate not much yet but supposedly that takes longer. I've begun working with their Reef care program. For a novice like myself their guidelines really help.
Algae is under control.
Also have balanced the pH and alkalinity which were off.
The corals seem happier. Hope the tang will also be relieved some.
Thanks to all and will update as things progress.

 

Just a quick update. After adding vitamins and working on stabilizing the water parameters the tang appears to be healing. Areas that were raised and white are now showing some signs of normal color and texture. He's not healed yet but appears to be on the mend, moving around enough it's hard to get a follow up photo.
Thanks to all for the good advice.

 

Thanks for the update. Glad to hear it.

 

Great news ..Keep it up.

 

Wanted to let folks know that the tang has healed since soaking food in Selcon solution before feeding. He had open sores which are now completely healed over. You can see the shadow where the wound was, he has a scar, but the skin looks normal now.
Hope this helps others.

Sorry it's blurry but he won't pose!

 

That's great news! He's doing what a tang does best