Completely agree to ALL the advice given here.
The most important bit of advice was -- return the fish, and start over.
That is unless you plan on purchasing a bigger tank, in which case you might be able to keep two Gourami's. That would be an absolute minimum of 55g, and that's still risky.
How long did you say your tank was running for with readings of 0,0,0? That seems almost impossible if you've had it up for almost any amount of time.
Anyway, the main thing you should take away from all this advice is-- return the fish, and start over. Otherwise you are going to kill them.
EDIT: Sorry, just saw that you aren't going to return them or get a bigger tank. I guess just pull up a chair and watch them croak. Sorry, just the truth.
130g: 7 Angelfish, 1 Bolivian, 17 Neon Tetras, 14 Serpae Tetras, 9 Kuhli Loaches, 1 Otocinslus, ? Ghost Shrimp
I've noticed that people HATE it when you point out how stupid they are, so now I try to do it politely.