My new gsp is sick

[GspLover]

Ph 8.2
Ammonia 0
Nitrites 0
Nitrates 5
Salinity 0,buying salt soon to start bringing it up
38 Gal. Marineland empoer 280 filter with activated carbon,Rena smart heater,and an 18 in. bubble wand with two 1.5 in. gsp's(getting another tank soon)
Fed Krill past two nights,did a 10 percent water change one day ago.Don't remeber the name of the conditioner I used,but it has a slime coat in it.
Tank has been set up for about a month,and it was fishless cycled using bottled bacteria.

I bought the fish about 3 days ago,and both looked nice and healthy.I got them home and did the acclimation thing,and they were still fine.The first two days they ate like little piggies,but today Mr.Angry didn't want to eat.Mr.Angry would turn grey at the edges whenever we would go up to the glass for the first two days,but go back to white after we would leave.Today when I went to check on them,he did the same thing,but it never went away.As the day went on it got worse and now his green is dark grey too.His eyes are sunken in,or maybe his body is swollen,I can't tell.I did net him and touch him through the net and he's not squishy like it's air.I tested the water twice today and the params. were as stated above both times.He is swimming around the tank,but it's slow.He's also been spending alot of time in the corner at the top of the water by the filter,or in the bubble curtain.The other one(Peter)is just fine,he ate,and is as lively as ever.I did notice that Mr.Angry had an odd colored patch of skin near his tail after we brought him home.It looked like a scar.I thought I saw some carbon floating in the water,but I couln't tell if that's what it was,maybe he ate some and got sick?.I did net out what I saw though.Maybe c 02 poisoning?
Sorry for the long winded post,I'm just worried about what I should do,I was thinking about putting him down with the half frozen water in a bowl,but wanted to see if I could help him first.

[LilGreenPuffer]

Don't put him down yet! Nonono! There are amazing people here who know just about everything about puffers. I am not one of them. Stick around for another half-hour or so, and someone will be here to help!

Go ahead and do a nice big water change, at least 50%. Maybe there's some icky in the water that you could get rid of that way. But it's not affecting the other fish... odd. I remember a post about a similar condition. The eyes were sunken, too. It was a Figure Eight. Try searching old Hospital posts for that, with keywords like "sunken eyes."

Has the funny-looking patch of skin changed at all?

[LilGreenPuffer]

viewtopic.php?f=3&t=16858&st=0&sk=t&sd= ... unken+eyes

Here it is! Do search the whole Hospital, though. I saw some similar-looking topics.

[marksrush]

Don't put him down yet! As one of the forum members often says, "Where there's life, there's hope."

I used some conditioning product with a slime coat additive once on one of my puffers, and he reacted *very* badly to it, similar to what you're describing. Just a thought. Now I only use Amquel+ for conditioning my water. I would do as LilGreenPuffer says, and change the water by 50% or so, and this time just use bare dechlorinator, no added junk, and see if that helps him.

[GspLover]

Thanks for the help everyone,I went ahead and put him down though.When I got home and checked on him,he was laying head down in the plastic plant by the bubble curtain and barely breathing.I got my net out to see if he would swim around.He tried,but he was bumping into everything like he couldn't see and there was some blood in his right eye.The odd colored skin didn't really change at all,it just got darker when his green skin turned grey.Peter is still doing just fine,and I did do the 50% water change.I will go out and buy a dechlorinator with no additives though.Thanks again.

[marksrush]

Darn.

[LilGreenPuffer]

Well, that's too bad.