I have two plecos I’m raising. I have leaching from new driftwood for about a month now and even my albino cats look darker. Could red streaks on pleco be a problem? Thank you, I love my little bristle nose plecos.
Red lines in the fins is an issue but I don't see that on the fish in the pictures.
The pinkish skin colour is fine for albino fish as long as it's all over the fish. If the fish had a pink patch on one side that would be an issue (maybe a bacterial infection).
Tannins don't cause problems to fish, it just discolours the water and makes it harder to see the fish.