FW dip is typically heated RO water i like tap dechlorinated because its typically closer alk and ph then RO. your fish will most likely freak out and act like it is dying when you put it in, mine always did. as for fungal infections sounds like same treatment in a brief search of the subject.Got some rally from chewy no other options att. Hope it gets here soon. If I can catch her I will put her in the 29 tonight. Part of me thinks treating the whole tank may be a good idea just in case. What's a good bacteria/fungus treatment. I have prazi. And when they say fw dip do they mean rodi or just fresh clean saltwater?