Why do my guppies keep dying?
Im new to owning a fish tank and ive come across my first problem that my guppies keep dying. Im not sure what exactly it could be as ive been trying to figure this out for a bit. My water parameters are a bit fudgy i think??(not really sure, if you have advice please let me know i appreciate it lots!)
Ive had this tank for maybe two months now, i water change weekly and havent been having any issues until recently :((
About my tank, recently, over a couple days one or two small male guppies would die. Ive noticed a faint grey ish mark on their sides (similar to a nip wound on a fish, but i dont believe i own anything in this tank that would do that?). ive only seen the small male guppies with this and dying, my larger females seem unaffected and continue to eat pretty well, another thing is i dont see this on any of the other species i have in this tank nor have i lost any other species in this tank in that way.
Im thinking it might be columnaris? And if so, how should i treat it??
I appreciate any and all advice! Thank you!
(Also im sorry if ive offended long time fish owners, im really new to this and im doing my best to follow all advice and learn im so sorry 😭)