white cottony stuff on her fin

Question
QUESTION: Hi I have two Jelly Bean Parrot fish in a 28 gallon tank. The girl, I know she is a girl because she lays eggs.She has just a little white cottony stuff on her fin. First I tried api fungus cure, it turned the water green, I did exactly what the directions said. It cleared it up but, came back a couple days later. So, I am trying the api pimafix, Am I doing the right thing? She will be about 2 around December and she is about 6 inches long. I just don't know what I am doing wrong! I do 20% water changes weekly and keep the light on for about 12 hours because I just love watching them. I not sure how much info you need or what she has. but I am concerned because I am attached to her! What should I do? Thank you.

ANSWER: You are doing hte right thing bhut might not be doing it long enough. If this continues, but her in a bown or something and completely clean the tank

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QUESTION: If I take her out and clean the tank, do I do a complete water change? Will that shock her? What does this white fluffy stuff sound like on her fins to you? maybe it is not a fungus. Can you recommend another medicine? Thanks.

Answer
If you let the tank regulate like you would a brand new one it may not as much but right now you don't have a choice. And I've always like the medcines made by Mardel so stick with that brand and if that doesn't work I could come up with a much more aggressive treatment