My Sis's Betta Seems To Be Sick! Help!

[Eines]

This is the first time I've ever tank care of a betta. He's in a 12 l tank with a heater, but no filter or gravel. I bought him 3 days ago. Today, I did his first water change. I removed 50% of the water with a vaccum thingy, cleaned the tank, and refilled it with water that had been dechlorinized and had the same temp as the water he was in before. However, now, several hours later, my sis noticed that he is looking strange. He is usually a very dark blue, but now his body is a pale grey-ish purplely pink color and his pupils look...funny, sorta dialated. He won't eat anything, even though this morning he was still eating and blowing bubbles; and I'm worried! Help! Does anybody know what's wrong and what I can do?

Here are the results of the water test I just took:
NO3 mg/l = 25
NO2 mg/l = 0
GH = 7
KH = 10
PH = 7
Temp = 26 C

 

[stang1]

Have you got a reading for Ammonia and are you using a liquid or dip test kit?

 

[Eines]

Dip test. And for some reason, they don't sell ammonia tests in Germany. Honestly, I've looked everywhere for them, but can't find any. I've never had a problem cycling a new tank though...and the nitrite and nitrate readings seem pretty normal...

 

[stang1]

If you can get a liquid test, it would be so much better. Dip tests aren't very reliable and tend to be fairly inaccurate, I'm afraid.
Has he got plenty of hiding places and somewhere to rest?
My boys like to rest on the leaves of the Anubias and I've got bogwood and stone so they have somewhere to hide.

 

[Eines]

He's got a plant with medium sized leaves. I suppose I could buy a cave or something for him tomorrow if you think it would help...? Still, I mean, he was blowing bubble nests and acting perfectly normal until this morning, so I don't see why that should suddenly bother him!

 

[stang1]

If he's building bubble nests then I doubt there is much wrong with him. Never hurts to have hiding places though as it makes them feel more secure.
Fish are as strange as us humans and they can change their temperament quite easily. One of my boys was in the end compartment of my divided tank where there was constant activity from us going in and out of the room. He was fine for months and then I noticed he'd started to chew his tail. I moved him to a quiet part of the tank, his fin healed and he's right as rain now!

 

[Eines]

Hmm...thanks for the encouragement. I'll keep an eye on it though! Maybe it was just the stress of having his water changed...

gotta go to bed. g'night.

 

[stang1]

Give him a few days and he'll probably be fine.
Let us know how you get on.