Entire Tank In Jeopardy?

[mybutterflyiris]

I wasn't really sure if I should put this here or not, but for lack of a better place it is.

I am a college student with a 25 gallon tank with 2 giant danios, a 6-7" pleco and a recently added figure eight puffer (got on Tues.). Last night it got a little chilly in my apartment. So before feeding my fish I was checking the aquarium heater ( thermaflow, modelcnn-plax) and making some adjustments when the entire glass tip broke off and fell into the aquarium. I think it was just old and brittle or something. Anyways, now I don't know if all of my water is contaminated or not? A small cloudy puff of whatever resides inside of a heater went out into the water. Now naturally you would think that it's better to be safe than sorry and just change out all the water. The problem is the only aquarium bucket I have only holds about a gallon and I don't have any salt (puffer requires) since normally when I do big water changes my mother comes down to bring me a hand and brings that stuff. Plus, I fear stressing the puffer more.
*feels hopeless*

 

[mybutterflyiris]

Ug! *gets ansey. Maybe people don't understand my question. It boils down to if the stuff that is inside the heater is toxic to the fish.

*runs off to continue search for friend with clean bucket*

 

[WILDER]

Also plus the water changes add some black carbon to the filter, if already have one in add a new one, how are the fish acting.

 

[mybutterflyiris]

Thanks for the reply.
I have removed all the fish. They are all bagged in clean water, but they are going to have to be okay for awhile as they won't be getting back into the tank untill probably around 4:00 unfortunately. *holds breath
The puffer is the only one I'm truely worried about as I've never previously had a puffer and I only got him eating yesturday, so I don't like stressing him more. But without knowing anything about the contaminate I'm forced into a 100% water change/cleaning.

 

[WILDER]

Ok, good luck fingers crossed.