Not at all. Bettas come from naturally tannin-stained waters. They can be good for the fish's health also - exactly how is up for debate, but they seem to bring some antifungal/antibacterial benefits. As long as the PH remains stable, it's harmless.

 

Much obliged for your reply hygropunk. So far, the water parameters have remained the same . My Betta is active, not gasping for air and is as colorful as the day I introduced him to his new home.

 

Unless there are enough tannins to reduce the light available for the plants, a rare occurrence.

Michel.

 

Not only are tannins not harmful, they’re actually extremely beneficial. Some die hard advocates would go so far as to say they are an essential missing link in softwater aquariums. Tannins/Humic/fulvic acids may even play a large role in how fish are able to survive in ultra low ph environments. They are natural chelators that help make nutrients available to plants, they help bind heavy metals, and some botanicals like Indian almond leaf have strong anti-bacterial and anti-fungal properties.

You always have to be cautious when adding organics to a closed system, but I swear by the use of Indian almond, alder cone, and other humic extracts. Glosso factory makes a nice premade mix call darkwater as does dennerle called Humin Elixir-both if which do not really stain the water too bad. I use both intermittently along with a homemade brew and try to keep a few Indian almond leaves right in the tank.

Don’t fear the tint!