Pop-eye - Maracyn Two treatment - Fancy Goldfish

Question
QUESTION: Hi!  Marian, again!  Two of my Goldfish have Pop-eye and one with Columnaris.  I first tried 5 days of Maracyn, then I tried 5 days of Maracyn Two.  Tomorrow will be my fifth day on Maracyn Two.  The two fish still have their eye's popped out.   My Black Moor has one more advanced Pop-eye.  My fantail has both eyes affected, but not too bad.  The Columnaris on another Black Moor looks like it is gone, now.  I don't know if you told me, or if I read it, that during Pop-eye, keep aquarium lights mostly off.
Questions:
#1 - I have used Maracyn for two times, now.  They still have Pop-eye - when can I treat for another two times with Maracyn Two, as package says treat only two times, but fish's eyes aren't any better.
#2 - If eyes don't get better, how long do I leave tank lights off?  Forever??
#3 - How long are Goldfish lights supposed to be on, daily, when fish are O.K.?

ANSWER: Marian,

It will take some time before you see that the medication is working. Just follow the directions on the medication then wait a week or two and we will see how things are going. By the time we see the signs of pop eye whatever has caused it has been going on for a long time. Let me know how things are in about a week.

---------- FOLLOW-UP ----------

QUESTION: What about my other question re:  keep lights off in tank while fish has Pop-eye?  Do I leave them off and put them on after two treatments with Maracyn Two?  Or, leave lights off until all the Pop-eye symptoms are gone?

ANSWER: Once the treatment is done you can turn the light back on. Leave the light on no more than 8 hours a day.

---------- FOLLOW-UP ----------

QUESTION: Hi!  I wanted to know if I should put 4 tablespoons of aquarium salt in my 50 gallon tank, or not.  I have just yesterday finished treating Pop-eye with Maracyn Two for two sessions.  The Pop-eye is not any better, but you told me it may take a while to see improvement.  Would the Salt harm the Pop-eye fish (2 of them) or any of my other fish?  I have used Aquarium Salt in the past with the fish I have.  But, I don't know if the Salt would harm these two fish or not.  I also have = Fancy Goldfish; Cory Catfish; algae eaters; Pleco; and a Betta.  To-day, I vacuumed the gravel, took 3 buckets of water out; put new charcoal in two Aqua Clear 70 filters.  I just don't know about the Salt now.  Will it harm the Pop-eye fish or help them heal?

Answer
The salt can harm your cory cats. You also have a mixture of fish that should not be in the tank together. Your goldfish is a cold water fish and the Betta, cory, and pleco are tropical fish. You will need to remove the goldfish and put it in a proper home.