Contaminated Tank?

[Michael[91]]

So my tanks is finally cycled, and yesterday I decided to go to petco(bad choice, i know never doing it again) to buy a F8, first think i noticed was Ich so since i was planning on keeping F8's with mollys i decided to buy two balloon mollys, came home, excited, put the mollys in and eventually realized while one molly looked fine, the other had dryish, crispy skin around his head and i immediately knew something was up, so after keeping him in my tank overnight( i didnt have a choice) I took the sick molly back and the manager of aquatics at petco told me that it was mouth rot, so now im scared that my water may be infected, what do I do? Do i hold off on getting the F8 until next week or what. I dont want him getting sick, and im especially worried about my water and the "healthy" molly.

Oh and i forgot to mention i did a really small water change today, just to clean the gravel and get rid of uneaten flakes by the previous inhabitants, 5 danios.

[LilGreenPuffer]

Clean water will keep the others from getting mouth rot. But I don't think that the employee had a correct ID.

Here's an advanced stage: http://www.practicalfishkeeping.co.uk/p ... th_rot.jpg

An earlier stage: http://www.animalnetwork.com/aquariumfi ... ungus5.jpg

[Pufferpunk]

I'd start by treating the puffer for a week with Melafix will also reduce stress.

[Michael[91]]

Yea, youre right thats completely different then what the molly had, he just had dryish crusty skin rather then smooth shiny scales, i first took him to my lfs and the manager there even said he cant identify what the fish has cause hes never seen it before, but it didnt look normal. I'm worried my waters messed up and this molly might be sick, but idk, should i hold off on buying the F8?

[LilGreenPuffer]

Yes.