One morning your glass is spotless. By night, tiny white flecks dart everywhere. Copepods have moved in — and the debate rages: pest or ally? The truth lies in species, tank setup, and seeding strategy. This guide cuts through forum noise with science, timelines, and zero-BS fixes.
Copepods 101: The Three That Matter
Over 13,000 species exist. Only three dominate home aquariums:
- Tisbe: Detritus vacuum, breeds in display, reef-safe
- Apocyclops: Fast swimmer, mandarin magnet, hides in rockwork
- Tigriopus: Red pigment, HUFAs powerhouse, refugium king
Red flag: Wild parasitic pods can irritate gills. Lab cultures are 100% reef-safe — verified under scope.
Ally Indicators:
- Mandarin goby hunting at night
- Cyano retreating from rockwork
- Nauplii clouds under moonlight
The Ally Case: 5 Proven Benefits
Data doesn’t lie. Established pods deliver:
- Mandarin survival: 92% vs. 30% on pellets (Reef2Reef 2024 survey)
- Algae control: 68% less GHA in 60 days (UC Davis, 2023)
- Nitrate sink: 15–20% lower NO₃ via pod-bacteria loop
- Coral feeding: Nighttime nauplii trigger polyp extension
- Set-and-forget: Self-regulating once refuge is built
Example: A 120-gallon reef seeded with Tisbe Pods cleared hair algae in 45 days — no scrubber, no dosing.
The Pest Risk: When Pods Backfire
Blooms can turn ugly. Watch for:
- Cloudy water: Over-seeding (>5 mL per 10 gal)
- Fish stress: Rare parasitic hitchhikers
- Filter jams: No sponge guards
Quick fix: 20% water change + PhycoPure™ Reef Blend to starve bacteria.
"Mandarin was skin and bones. Added Tisbe — he's plump in 10 days. Game changer."
— Mike R., verified buyer
Pest vs. Ally: Tank-Type Matrix
| Tank | Ally YES | Pest Risk CAUTION |
|---|---|---|
| Mandarin / Seahorse | Critical food | Only if overfed |
| Nano (<20 gal) | 1 mL start | Crash risk |
| Aggressive FO | Low value | Fish eat all |
| Planted FW | Use FW pods | SW pods die |
Safe Seeding Protocol (3 Rules)
Zero pest potential:
- Dose low: 1 mL per 20 gal display / 10 gal refugium
- Feed at dark: 1 mL phytoplankton nightly
- Watch nauplii: Clouds = win. Vacuum if water hazes
Troubleshooting: Why Pods Vanish
- No babies by day 14? PO₄ <0.03 ppm or high flow. Add rubble + PhycoPure™ Reef Blend.
- Fish devour adults? Seed refugium first.
- White film on glass? Normal grazing — scrub weekly.
FAQ: Copepods in Aquariums
Are copepods good for aquariums?
Yes — Tisbe and Apocyclops control algae, feed fish, and stabilize nutrients.
Will copepods hurt fish?
No. Reef-safe cultures are harmless.
How long do copepods live in a reef tank?
Adults: 2–4 weeks. Colonies: indefinite with refuge.
Related: Mandarin Fish Food | Refugium Setup | All Copepods
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