Sickly pearl gourami -salt?

[Sgooosh]

Hi! I have this weak little gourami who always has trouble with fin rot, and recently I put it in a quarantine with some baby fish from outside that I recently moved in.
It turns out she got worse because the little platy was bullying her.
I took out the platy (rest of the fish are medaka and guppy fry) today.

I'm wondering if pearl gouramis can tolerate salt for them to heal?
I will be using @Colin_T 's formula for aquarium salt.

she always gets nipped whenevr I put her back, so I think she'll just be a resident of the QT tank until she grows bigger and stronger.

 

[Colin_T]

All freshwater fish can tolerate 1-2 heaped tablespoons of sodium chloride for 2-4 weeks.

If the fish is small and weak and not doing as well as the others, it could have worms, gill flukes, another health issue, or might be a genetic runt. You should try to rule out as many of these issues as possible to work out why it regularly has problems.

Regular fin rot on the same fin could indicate an underlying bacterial infection or a fish that has a weak immune system.