Guppies and fin rot??

[Caitie]

So I don't know what the eff is going on but I'm losing just guppies left, right and center. But nobody else is affected so I cant tell if its a fungus or bacteria or a bully in the tank... It was happening before in my 15 gallon when I had just a couple guppies, especially cobra guppies ... their tail starts out with a bit of a tear and then later on or the next day would be shredded and eventually not there. So I thought it was my bleeding heart tetra and I moved him from the tank but it happened again so I put him back. Then I thought it was the filter sucking them up because that's where I found the last one dead. So I got a foam cover for the filter and it hasn't happened there since... but then this was happening in my 5.5 gallon and just yesterday I lost 3. After the first one died I took the foam cover from the 15 and put it in the 5.5 and then hours later I found 2 more dead ... I should mention too that those 3 are all newer guppies from 5 I just recently got from a local aquarium and not my usual place. All 3 had barely any tail and the first one I found was encased in like white cloudy moldy looking foam... so I did a 30% water change and all the other guppies look fine and are thriving ... Im so confused and so worried, Im taking a water sample in to get checked today but I want to see what you all think?!?!

 

[Delapool]

How did you go with the water sample? Do you have anything else with the guppies now? To shred that quick I do wonder if another fish is having a go at them.

 

[Matt68005]

You have to find out if its fungus or columnaris bacteria. To me the "dieying left and right" sounds like the latter.

 

[Matt68005]

Btw, finrot on guppy males is not a big deal. Its fungus and easy to get rid of with methylene blue. True columnaris is more of a clamped bent shimmying whole body brownish sort of rot, tho there are white lesions that grow on the dead skin areas. Early diagnosis powerful antibiotics and seasalt are the best cure for columnaris.