I would suggest one thing right off the bat, rehome the Goldfish. Goldfish with Tropicals in the same is problems waiting to happen. Goldfish produce a lot of urea(Pee) and this is very unhealthy for the Tropicals, especially the Angelfish.
Update need advice
Ok; did a 75% water change in my 30 gallon because had another angel pass.
Strip test: (ordering other)
NO 2 0
Alk 0- 80
Tested 20 gallon with bristle nose pleco
Please post a link to what all these parameters mean... Should I move the gold fish betta and tetras to 20 temporarily until Ivan figure something out?
Home with sick 2 yr old and can't really do much right this minute... Waiting on husband...