He has HLLE.., which most likely is caused by the use of carbon or water quality/nutrient issues but that won't make him sick like that. As to the discoloration, it's stress but also likely velvet which can kill in 2 days. It looks like you don't have coral in here so I think you should consider dosing either copper power or coppersafe. What are your water quality readings in ammonia, ph, dKH? The tank looks a bit tight for a sailfin and a blue tang. What else are in there? How big is the tank? Is the sailfin bullying the blue?
This is him this morning, still not acting normal. Swimming backwards, just seems completely disoriented.
As for the tank it has been set up for about 2 1/2 years. And we’ve had the tang for probably somewhere around 1 1/2 years.
The tank is a 70g with a 20g sump. We also have 2 clowns, a saddleback puffer, 2 damsels, and a snowflake eel. The sailfin usually leave the blue alone, except every few days they would swim circles around each other. But that only lasts for less than a minute, then they would go back to swimming around. As for readings I’m not sure as we don’t have a test kit. We have someone come out every 2 weeks to maintain the tank. And he checks water each time and as of a week ago all readings were good. We are going to take a water sample to our fish store where we’ve bought everything from . Also messaged the guy who maintains our tank and he suggested taking blue into the store so they can put her in a tank in back and Medicate her.
