Tea-Colored Pond Water: Mulch Tannins and Carbon Fix

Cause

900-gal pond, 6 months, reddish-brown "tea" color. Field stone shelves, river stone bottom, hardwood mulch around edges. Water hyacinths died. Tetra flakes not the cause.

Diagnosis

Mulch leaching tannins → tea color. Fresh mulch leaches heavily; ages out in months. Stone not washed → initial cloudiness, not tea.

Fixes

1. Activated carbon in filter (mesh bag). May need large amount. Replace when color returns.
2. Dense filter mats before carbon to trap fines.
3. Weekly 10% water changes dilute tannins.
4. Check pH: Tannins lower pH. If <7, monitor.

Bottom Drain

Not essential. Many ponds thrive without. Sucks up small life. Good for koi-only ponds.

Hyacinth Death

Likely from low light (tea color) or nutrient competition. Clear water first.