Male and Female Guppie Tail Rot or Not? Please Help Me I have more guppies!

[LibertyWolf]

So yesterday I found my female guppie floating in my tank upside down and sideways. I knew this woouldn't end well and found her completely still today. But that isn't*all I found as I found one of the three male guppies I have with his beautiful green tail gone and his colour on his body gone.

I don't exactly know what is happening but I have found out it could be my tank water quality or tail rot. Please help me

 

[Mebbid]

What are the parameters of your tank water? Ammonia, nitrites, and nitrates? How long has this tank been set up?

Regardless, i would highly recommend a 50% water change immediately then we can move on from there.