TL;DR - Get a PT, and stay away from Biota.
I have some anecdotal, as well as first-hand, information about Biota YT's. I have wanted a YT for years, but didn't have the tank size until they became unavailable. I got mine a couple days after they came in at my LFS. Picked the brightest and most active one. He was about 2". I asked if they were eating nori and/or algae pellets, and he threw some tdo chroma pellets in the quarantine tank. I asked about other foods, and he said he'd spoken with Biota, and this is what they'd been feeding them. I can't confirm they said this, but he's the owner, and he'd never given me a reason to doubt him. I should have looked closer at the ingredients since they're only coated with algae, and not a great option for Tangs IMO. They were small enough for his tiny mouth, so I didn't think about other foods during quarantine other than nori.
Wouldn't eat much nori, but would peck at the algae in the quarantine tank. HLLE came on quickly. Read reports that other Biota YT's were having the same issue. No other signs of disease. As I only had clownfish and a Ritteri anemone in my display (they're spoiled), and I couldn't find any evidence that clowns could be affected, I moved him out of quarantine after 6 weeks to give him more room, thinking it might be stress from a smaller tank.
It's now been a year, and the scarring is likely permanent. He's just gotten worse, no matter what I've done. I alternate four different types of nori (two green, one brown, and one red) Omega and Sushi nori. New strip twice a day. He gets Hikari seaweed extreme algae pellets, and since I can't keep him from eating the clown's frozen foods, I dose those with a couple drops of selcon. He eats well, and he's plump. I can't see any sign of the stringy spironucleosis feces, but I'm about to add Metronidazole flake food temporarily. So that'll make 10 different foods I keep track of for three fish and the nem. Considering sending off an ICP test just to see if there's anything else I may have missed, but since the rest of the tank is solid, I gotta point the finger at Biota.
There's a grounding probe in the tank, and no stray voltage. I use Tropic Marin Pro Reef salt. Weekly Sunday 10% water change. No high NO3 or PO4, and KH, NaCl, Mg, Ca are all stable. All-for-reef is dosed (mostly for trace elements). Everything else thrives in the tank (Ritteri, clam, zoas, torch, and gsp). The Biota Yellow Tang is the only variable.
I'm now about to shell out for a 230.6 Waterbox just to upgrade from 4' to 6' for more room to swim. I guess I have too much empathy for my pets, but having a 20 year old clownfish has turned me into a softy. Biota has cost me a ton of money at this point with no end in sight. I will never intentionally buy another fish from Biota. It's been heartbreaking.
