Should I add tannins to my tank?

[Navfish]

I just purchased a botanical starter pack with alder cones, Catappa leaves, twigs, etc. I used to put botanicals in my betta tanks but do tetras and guppies like tannins since I'm planning to put them in my guppy and tetra tanks?

Does it also matter how much I put in over time as well?

 

[Byron]

Tannins will not harm fish, and some species even benefit from them. The tetras are the most likely candidate, depending upon species. Those from blackwater will obviously thrive with tannins.

Another aspect is fish food...leaves, twigs and cones will host infusoria, the absolute best food for fry, but all fish will graze these surfaces, some more than others.