Velvet in tank

[saltwaterNano]

I have a 14 gallon nano tank, saltwater, I used to have two clown fishes, a royal gamma, a gobbie, a couple of hermit crabs and snails. My water parameters were perfect, haven’t introduced anything new into the tank. Then randomly my fish started dying one by one, don’t have the space to quarantine them. I thought it was ich but now I’m pretty confident it’s velvet, my last remaining fish which is the gobbie is struggling, any ideas on how the heck my tank got infested

 

[JumboShrimp]

Unfortunately, one bad fish is all it takes-- and if it's Marine Velvet, you've just stepped on a land mine. :(