We checked both puffers and saw the smaller puffer had a circle on her back that appeared to have been a bite mark. She was bit one other time at feeding a few weeks ago (treated one week w/ melafix) and this mark sort of resembled the same appearance although this time it is in her green area so it does look somewhat different because the first bite was in the white area of her belly. Another thing I do not see is the 2 tiny holes I saw in the first bite. We added melafix.
I need to know is there any disease that would look similar to what I am seeing. No other symptoms as of yet. Both are eating normal. They are fed 6 times a week raw shrimp, krill once a week, bloodworms, just added cooked snow crab to their diet this week for the shell and small snails once in a while. They are both under 2 inches big. In fresh water atm.
We have been having mini spikes atm. Doing 50% water changes up to 2 times a week. Tested water this morning:
Tank has been set up a month. Tried to cycle with bio spira.
55 g FW tank atm 2 baby gsp only
nitrate 20
nitrite 0
gh 150
kh 120
ph 7.8
Temp steady 78
Decor the normal stuff, fake plants, large bridge with lg holes for fish to swim into ect... I do not know of anyway this fish could have been injured in her tank other then by the other puffer.
I'm hoping someone can tell from the photos what is on her back. Is there any disease that would look similar?
Note the white mark on her back. I can't get any more pics up right now due to my host not working properly. I do not see anything else not normal on her right now. She is not covered with any other white marks anywhere.

[Edit] Picture was not showing. Put picture back in post.
