When breeding fish I have used tea bags, oak leaves, oak bark and brown water from streams on the west coast---all with success. If the fish were strssed out I suspect they would not breed. Others use alder cones or Indian Almond leaves with success I believe. With fish keeping we need to be sure to avoid anthropomorphism as I am sure that a coffee drinker like me would get pretty stressed out having to drink tea (or Indian almond leaves for that matter)
We have people down here breeding thousands of neons, rummy nose and other tetras in tap water.