Hi all it's been 3 weeks and my 3 albinos have been eating and putting weight back, so that was a huge relief.
One of them however has developed this white thing on its caudal fin that won't go away. I thought it was injury from pecking at first, but as you can see from the pics it's gone worse, and there's a bit of white stuff (I can't tell if it's fungus or not) that has grown from it for about a week now.
The 3 albinos are the only occupants in my 33G and I've been doing 90% WC every other day.