I have to say, I don't know if this fish tank experience could have gone any worse. :( I now have 2 very sick guppies, a most-likely infected main tank and a soon to be very disappointed little girl....

To backtrack, I started with one danio before I knew about fishless cycling, added another 2 danios way too early still not understanding about the nature of the cycle, lost one but the other 2 spawned and I now have babies in another tank. I then learned how difficult it can be to feed them and when I broke this to my daughter she was very upset. The girl at the LFS told me livebearers are much easier and that maybe baby guppies would be fun. My tank seemed to be nearing the end of cycling based on what she (incorrectly) told me so I got two gravid female guppies. The first to give birth has one funky gill. The gill plate never closes. This is what leads me to suspect gill flukes. That one also used to seem to have a hard time figuring out which way was up, especially when I turned the lights on, but as she acclimated to the tank, she seemed to get better. The other one seemed robust and healthy. Then one fin started looking ragged and I started Melafix as advised by the LFS employee. Then yesterday I noticed her fins and tail are clamped. Today she is listless, and suddenly covered with shaggy looking things all over. I believe we have gill and body flukes. The sick guppies are now in an emergency hospital tank being treated with Clout, which I'm hoping will not be too harsh for them. I chose that because I wasn't 100% sure what they have and they declined very rapidly from yesterday to today so whatever is causing the illness has to be killed immediately if they have any chance of survival. The poor very sick female still appears to still be gravid although I doubt she will survive to give birth. The two danios and the guppy fry (in the net breeder) in the main tank seem to be fine but I'm afraid that the tank is now contaminated and that they are all doomed. The tank they were all in is a little 10 gallon tank, a few weeks old. I've been able to keep my cycling mistakes in check with frequent water checks, with amm never going above .5 ppm. Nitrites have always been 0. Nitrates I forget but not outside of a safe range. I recently added lots of live plants (cambomba and frill) to try for a "silent cycle". My pH is high and my water is hard, if that is of importance to any of you.

I am so sad for my daughter. I made so many mistakes in this endeavor and she will take it so hard if these fish die. I am kind of wishing I never got any fish. :(

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10 g planted community, 10 gallon danio/RCS tank, 10 g ghost shrimp grow out tank, 10 g blue pearl shrimp tank, 75 g in the works.

In doing more online research I'm thinking maybe columnaris based on the look of my fish and one fish I noticed in the tank at the LFS today from the same tank had a raised white patch on the entire tail. Guess I need to find a new fish supplier, but what to do now?

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10 g planted community, 10 gallon danio/RCS tank, 10 g ghost shrimp grow out tank, 10 g blue pearl shrimp tank, 75 g in the works.

1. Take heart, I'm betting a majority of the experts on here have faced what your facing now. We all start pretty much from scratch and develop our knowledge base over time and plenty of mistakes. My first foray into the hobby was in the early 70's!!!!!!!!!!! Yikes I sound like my pop and his stories about the depression era!.. Luckily today the wealth of information on the net has been an incredible boon to the hobby. Sadly today, the dearth of family owned pet shops has left a lot of folks limited to stock from a big box store. Only after in the hobby for a while does someone develop the comfort of buying stock online or expanding your circle of acquaintance's to the level that you find home breeders.
So hang in there, take heart that you've already accumulated quite a bit of knowledge. Bill in va.

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12 Tanks, 900 gallons. Discus/Angels/Malawi/Lake Victorias. Just added a 135 & 2 - 29's..

Sorry to hear things are rough, but kudos on the effort to keep them alive and your research.

I'm not familiar with columnaris but others on here are. For your main tank, you might want to consider tearing everything down, throwing out the old filter material, and clean the gravel and filter with a weak solution of bleach and water. For the plants, washing them in a weak solution of hydrogen peroxide should wipe out anything in their leaves and stems. Don't wash the roots though. You could buy a cheap little 10 gallon to quarantine the danio and fry in and keep on the frequent water changes in the 10 gallon while you re-cycle the main tank with a fishless cycle technique.

That's just my thoughts, I hope your fish turn out ok, both for their sake and for your daughter's.

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Officially fishless until after the move....tune in later for details!

Sounds like saddleback columnaris from what you describe. I've never broken my tank down from it and it has never wiped out my entire stock or passed to another fish back when I was experiencing that disease. It was always new fish that had it. If they have the small worms coming out of their vent, that is a different story.

There are "claimed" treatments out there. I have one from Jungla Labs that I can't remember the name to and not at home to look. I have never been successful in treating a fish for it.