Pleco Have White Pimples On His Right Fin And Tain

[Mysteryimpt]

Hello guys,
I just realized something today. While I was feeding my fishes I have 4 tropical fish tanks:

5 gal Guppies tank - has a pleco which has white pimples growing on its tail. Moved it into a different small 5 gal tank for now as i didnt want the disease to spread.
10 gal platty tank - had 2 pleco one of the pleco had white pimples growing on its right fin. its really gross. Other one is fine for now. Moved it into a different small 5 gal tank for now as i didnt want the disease to spread.
10 gal Molly tank - has a pleco and its normal for now "knock on wood"
5 gal tetra tank - pleco is fine and no thing on it.

I dont know what caused these gross things to grow on my plecos. and its not from ONE tank but 2 different tank and the tank I had 2 plecos in, 1 had the plimples and other didnt.
Its really weird and its confusing me I dont know what to do to cure it. I have little guppies and plecos in my tanks and I really dont want them killed cause of this. Kindly help me and as I dont come on here that often kindly feel free to e-mail my with your thoughts I will really appreciate it thanks

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