Angels And Tetras Dying Please Help.

I need some help, my wife’s tank with her angel fish, barbs, and tetras arendying, over the past two days 2 bleeding heart tetras and 2 angel fish died, I noticed at first they were all swimming to the top of tank looked like they were gasping for air, I have an overhead filter and also air bubbler so I think they have enough air, and before the tetras died I noticed little air bubbles all over them, as well as on the angels, they started swimming sideways up upside down, I have done 2 water changes. All I have is test strips the only thing that is off a bit is the nitrate. Any help would be greatly appreciated. My wife isn’t very happy, it is not a new setup we have had all these fish in there for over a year. 2 weeks ago she got 2 very small cherry barbs, and they died so I think maybe they had a disease or something?

 

Sorry things aren't going well :-(
If the cherry barbs are the culprit, which they may be, this is exactly why we quarantine new fish.
Do your strips test for ammonia? There seem to be a lot of testing strips that test for everything EXCEPT ammonia....which I just do not understand! Ammonia is the first thing I test for if my fish are acting strange.

 

Whats your water parameters?

 

Thank you. I know my wife is pretty sad we have had them for quite awhile, and no the strips do not test for ammonia which I find stupid as well. And it is a holiday here today so I can not even go to a pet store or anything. First thing I thought was ammonia poison as well because that is what all the sypts looks like, there fins are starting to get red spot on them and little air bubbles on them. The pleco looks fine but is acting strange swimming back and forth as well and going to the top a lot..I had read of it is ammonia to change water I have done 2 water changes since yesterday afternoon changing about 40% each time..

Tha tank is 60 gallons 36” L x 24” H x 20” W

 

You could have ammonia in your tap water which wouldn't help things along much if it is an ammonia issue. (I have .25-.5ppm ammonia in my tap) Just a thought.
Had you cleaned the filter recently by chance?

 

I had changed filters maybe 2 weeks ago at most, I just changed them today. And I know what you mean by ammonia being in our tap water. But that is the same water we have been using for over a year and have not had any problems at all. That’s why I was more leaning toward it being something to do with the small cherry barbs she had put in. Since last night 4 have died worse timing because everything is closed so even if I needed something to test with or something to add to water I can’t get anything until tomorrow

 

What do you mean you changed the filters? You removed both filter pads and added brand new ones? If so that's why. You just got rid of your cycle and how have to start over.

 

No I changed one, I stagger them every few weeks. So keep an old one in and then the next couple weeks replace that one and so on

 

Another angel has died... I don’t know what the to do.