Clearing Tea-Colored Pond Water Caused by Tannins

Source of the Color

Tea-colored (brown but clear) water comes from tannins and lignins leaching from organic matter: leaves, branches, mulch, peat, or soil. Mulch near the pond is a prime suspect; it leaches heavily when new, diminishing as it ages.

Dirt vs. Tannins

Dirt makes water cloudy brown. Tannins make it clear brown. Your description suggests tannins.

Solutions

• Activated Carbon: Place rinsed carbon in a mesh bag in the filter or any moving water (even directly in the pond). It adsorbs tannins effectively. Replace every few weeks until color clears.
• Filtration: A proper filter helps remove particulate organics. Even a simple box filter with carbon helps.
• Water Changes: Dilute tannins with partial changes (use dechlorinator).
• Source Control: Divert runoff, remove excess mulch from pond edges.

Rainwater Note

Rain itself is not brown. If your front fountain also turns brown after rain, check for algae (brown algae likes shade) or debris washing in. Tap water should be clear.