How is she? Yes, Epsom salt can be used for popeye. Since you have a 5 gal tank, here's a relatively easy way to add the correct amount:
- Put some tank water in a cup. Add 2.5 teaspoons Epsom salt. Stir until the salt is completely dissolved.
- Slowly, over the course of about 15-30 minutes, pour the solution back into the tank. (This will yield a dosage of 0.5 teaspoons Epsom salt/gal.)
- After 10-12 hours, repeat the above process. (This will yield a dosage of 1 teaspoon Epsom salt/gal.)
When doing your regular water changes, dissolve Epsom salt into the new water at a dosage of 1 teaspoon per gallon. (This will maintain the 1 teaspoon Epsom salt/gal dosage.)... For example, if you do a 100% water change, you'd use 5 gallons of new water (with conditioner) which would require a total of 5 teaspoons Epsom salt. (1 teaspoon per gallon.)
You don't need to add any of it between water changes. Salt doesn't evaporate. It stays in the tank until you remove it.
After you're finished treating her, just go back to using regular (conditioned) water without any salt. This will start to remove the salt from the tank.
*If the Epsom salt doesn't help her popeye within a day or so - I would recommend adding an antibiotic. The Jungle Fungus Clear that darkangel recommended would be a good choice. (Jungle Fungus Clear, API Furan 2, and Bifuran all contain the same 2 antibiotics. You could use any of those.)