Blackspot tang has white spot! help! pics!

Just found him this morning with a white mark infront of his eye. Its long and wide
So i dont think its ich. From my description please try to help. Will post pics later. On way to fish store so reply quickly

 

Please look at Lateral Line Disease.

 

Here are pics. i can not tell. it doesn't appear to be lateral line disease, but i am not an expert.



please help:-[

 

I think HLLE as well. But this is probably just the beginning of stress induced conditions from having a 20" growing fish in an 18" tank.

 

What is HLLE? and yeah... i realized he was going to get way to big for my tank after i looked him up when i got home from buying him. I plan on donating him to someone who has a very large aquarium when he becomes a little larger. I don't want him to suffer.

 

They are a rarer tang to find in the hobby and one of the best look as far as I'm concerned. Id just upgrade to a 265 and call it good. HLLE is Head and Lateral Line Disease. It cause is.... well... captivity. It doesn't happen in the wild. Nutrition, Stress, Bacteria, and a million other things add to the cause of this disorder. Tangs are the most susceptible. My lavender tang is prone to it more than any of my other tangs. The thing I've found to help out is soaking their food in Selcon. My tang had three big spots rot out and after three weeks of selcon treated food looked good as new.

 

I cant wait to tell my mom "in order to keep my tang in perfect health and happiness, i need to upgrade to a 265 gallon tank" thatll go over well! Haha. Now where can i get selcon? Will it harm any corals? Also what are the dimensions of a 265?:

 

265 info

Just tell your mom, "But Alex SAID!!!!!!!!"

 

I say that, and she'll say "Well is Alex gonna pay for the damn thing?!" ;D

 

but I've noticed the white spot has decreased in size since this morning