Black, Murky Pond Water: Filtration Upgrade Needed

Problem

6×3×? ft pond, black sides, murky water, lilies not thriving. Cleaned multiple times, no improvement.

Filtration Basics

Every pond needs three-stage filtration:

1. Mechanical (pre-filter): Removes solids (leaves, waste). Sieve, vortex, or coarse foam cleaned weekly.
2. Biological: Media for nitrifying bacteria (Japanese mats, Kaldness, bio-balls). Clean only when flow restricted.
3. UV Clarifier: Kills suspended algae. Size: 3 W/1000 gal. Replace bulb annually.

Your Fix

1. Install a proper pre-filter (e.g., sieve or settlement chamber).
2. Add biological media in a separate chamber.
3. Ensure UV is after biofilter, sized correctly.
4. Add marginal and submerged plants to compete for nutrients.

Quick Test

Jar test: fill clear jar, let sit 2 hrs. Sediment = mechanical issue. Green = algae (UV needed). Tea = tannins (carbon).