fish are not eating

bankai01

someone help please my 13 cardinals arnt eating. this have happened since yesterday. all tests are normal they seem to be healthy swimming around but just not eating.

Lupin

How long have you kept them? What foods were you using?

bankai01

alright cool, i have had them for 3 months. they have usually ate. i fed them tripical fish flakes. 2 days ago i have bought new life spectrum(pellets) and they seemed to be eating them fine that day. Last night i have noticed the Phantom tetra was bullying my cardinals(they turned black and harassed them and bit them) because the cardinals kept getting in their territory. So now i have scooped out the phantom tetras. Today..silly of me i have put my drift wood inside my tank after 4 days of soaking it in water. I think small particals effected the fish water causing the fish to rise up and grasp for air. Noticing that i have taken out the driftwood and it is boiling right now. And i preformed a 50% water change and put my air pump in the tank with a airstone on it.