Let me give you an idea who is right here.Hi. I think there is no saving the torch now but I would like to know exactly what caused this. Also my LFS say that right now with my current tank inhabitants, I could still add another tang and a few small fish. But I dont know who is right.
Firstly, we don't know you. We owe you nothing and you owe us nothing. We are just a bunch of people passionate about the hobby(as you see in the thread).
Secondly, the local fish store needs to stay open. They need paying customers. They need your money.
Thirdly, do some looking and do your homework. Just type in your fish in Google search. It will give you lots of information on the fish including tank sizes. Some bigger size, some smaller size. I tend to lean towards the bigger size tanks for any certain fish. You will not find one site will recommend either of those fish for a 20 gallon.
Try it.