Guppy Dying

[jace]

hello,
I added 2 guppies and 1 african dwarf frog to my 10 gal tank that only had 1 existing guppy in it 2 days ago. I quickly noticed that the existing guppy was very aggresive to the 2 new guppies, striking at them at times. Today I came home and my dwarf frog is dead, and 1 guppy is in very bad shape (his tail fin looks shredded, barely moving and not too responsive). The 2nd guppy is fine and interacting with the existing one fine. Is my 1 guppy pretty much lost or is there hope. Why did my frog die? Also a note I have very hard water if that helps at all.

Readings:
Nitrate 0
Nitirite .5
Ammonia 0
PH 7.8
Hardness / alkalinity = high

 

[WILDER]

Bad water quality.
Immediate water change and increase aeration.

How long has the tank been set up.
Males will fight sometimes, If males don't get on no matter what you do its best to rehome one of them.

 

[broessle]

i think your pH is too high for your frog. I believe they like it around 7.0-7.2 range. perhaps same reason for your problems with guppies

 

[WILDER]

What's your tap ph.

 

[jace]

What's your tap ph.

My tap water PH is 7.2
my tank has been setup for about 3 months. On a side note I had been doing a fish-in-cycling and it seemed to take an extremely long time. I have been doing about a 75% water change as needed to keep my nitrite and ammonia down.

 

[WILDER]

Your ph is fine for guppys not sure about the frogs.

Bad water quality can alter ph.
What ornaments and substrate do you have in the tank.