Clearing Dirty Water in a New 300-Gallon Plastic Pond

A new 3×5 ft pond (approx. 300 gal) with pump/filter runs 24/7 but water appears dirty, not green. No rocks, no fish yet. Likely causes: bacterial bloom, fine clay from tap water, or debris from the liner.

Diagnostic Steps

• Water color: Brown/white = clay or bacterial bloom; green-brown = algae.
• Filter media: Is the pad catching fine particles? Upgrade to finer floss.
• Source water: Well or municipal? High minerals cause cloudiness.

Quick Fixes

1. If no livestock: Drain, rinse liner, refill. Add dechlorinator.
2. Add beneficial bacteria (liquid or powder) to seed the biofilter.
3. Use a flocculant (AccuClear) to clump fines for filter removal.
4. Add plants immediately—floaters and submerged—to compete for nutrients.

New ponds often go through a "ugly phase." Patience, bacteria, and plants clear it in 2–4 weeks.