I got up this morning and it is still very cloudy and white. I had to leave for work before I could do another test. I added more stresscoat and stresszyme. When I get home tonight I will do another small water change probably around 20%.
You're just wasting your time doing a 20% WC. The tank needs upwards of 50-75% water changes at this point, assuming you can safely do that much ( meaning your tap water doesn't have ammonia in it). Why the stress zyme? I'd forget that and change lots of water. A WC is one simple cheap fast thing you can do that will immediantly make the fish feel better. That ammonia is burning their gills at this moment. Just my take!
That's a deadly level of ammonia. It's also really bad that you have nitrites showing up. Your tank is going through a cycle right now and if you want to save your fish you need to do some big water changes.
IMO your tank is under-filtered for the amount of fish you have in your 180. I run two xp3's on my 180 and they do a good job. IMO, those Magnums are almost useless in big tanks with big fish. Invest in some decent canisters.
Do you have any other tanks you can steal bio media from? Also, I don't like amo chips. Once you are over this spike, you should remove it completely. The BB neeeds amo to grow. If you are removing the amo, the BB isn't growing in the numbers it should. This leads to a weak bio filter that can cause a spike.
I agree that you need a large waterchange of more than 50%. Use Prime because it detoxifies ammonia, the stresscoat is not going to help.
I think this problem started because your tank was underfiltered and overstocked. Generally if the filter is rated for a 100g tank it's good for a decently stocked 50g tank. You should get a couple of Aquaclear 110 hang-on-back filters for something like $40 a piece (there is a sticky for this deal) and, like someone else said, invest in some good canisters because the Magnums won't cut it on your tank with your fishload. I think it's safe to say you wiped out a good portion of your BB's so it'll be a while before the tank is fully cycled again but you can speed this up by adding bio spira or media from an established tank.
If you can get your fish into someone elses tank, spread them out into quarantine tanks, or do large daily waterchanges you might be able to save them but keep in mind that large daily W/C's will inhibit bacteria growth and prolong the cycling.
I have lots of tanks and I will spread the fish out among them. I will also invest in some more filtration and I can borrow some established filters from other tanks.
As for the bio spira, I'm not familiar with what that is, a quick google only turned up a saltwater product. I used stresszyme because it is supposed to detox the ammonia and boost BB, but I could be wrong. I didn't have a problem the last 5 months the tank was running that's why I'm confused with what's going on right now, but its pretty hard for me to argue considering the current situation.