There is very little beneficial bacteria in the water column. Bacteria attach to surfaces (Rock, grains of sand, the glass, etc.). With ammonia reading 3ppm and fish in the tank a 50% pwc
is in order. Twice daily 20% - 30% PWC
's may be necessary to keep ammonia low enough to save the fish.
Take them home over the break and try to maintain the water parameters in a 10 gallon tank with 2x/daily pwc
's until the QT tank is cycled.
Take the time to visit some local LFS
and ask them about local clubs, and fill them in on your project. Especially at this time of year you may end up getting some equipment (test kits with near expiration dates, maybe even a piece or two of LR
or base rock, etc.). Get in touch with the local reef clubs, join them and let them know about the project. Many civic minded people would be happy to help. I know that if you were in my area I would be happy to donate some old equipment, LS
to your project. Heck, I'd even volunteer to help the kids out in school as the project got started.
You don't have to do this alone. But, you do need to do it the correct way to turn into a valuable lesson for the students.
The fish you have may have already suffered enough gill damage due to ammonia poisoning that they may not make it. Take that as a learning opportunity. Start again with the fishless cycling method and teach that to the students. It would be great if the end result of the project is a class full of students who decide to have their own piece of the reef at home, and know how to do that successfully.
I think I speak for everyone here in hoping for a successful project for you and the students.
Also, please update your profile with your general location. There may be members of this forum who are close enough to help.