Angelfish odd behavior

Question
Hi, I took 2 angelfish (a 1.5' silver and black and a smaller gold one) home and introduced them to my 30 gallon aquarium today, and after a feeding and another hour or so of just watching them they began to swim nose up, tail down hovering by the filter near the surface. I'm wondering if there is something I can do or if it could be just initial stress. any advise would be appreciated.

Answer
Hi there,
Sounds like a stress response. I would do a 50% water change and be sure to save some of the old water to test for ammonia, nitrite, and nitrate to make sure the aquarium has an established 'biofilter' to keep ammonia and nitrite levels at zero. Nitrate should be at 20 or less for a healthy balanced aquarium.

I hope all is well!
Karen~