High nitrate in a reef tank

If your nitrate keeps creeping up, the goal is stable, gradual reduction. Big swings can stress corals, trigger algae, and make the tank feel unpredictable.

Common signs

• Dull coral colour or reduced polyp extension
• Persistent nuisance algae
• Dirty sandbed or detritus build up
• Test results rising week to week

Common causes

• Overfeeding or heavy bioload
• Trapped detritus in rockwork or sump
• Weak export (skimming, refugium, water changes)
• New tank instability or immature biology

A safe plan that actually works

1. Confirm your test accuracy (retest, compare brands if unsure).
2. Reduce inputs slightly (feed smaller amounts, rinse frozen foods).
3. Increase export (clean mechanical filtration, tune skimmer, siphon detritus).
4. Use a controlled nitrate reduction product to support biological processes.
5. Re-test every few days and aim for steady improvement, not a crash to zero.

Recommended product: Nitrate Reducer

• Supports biological nitrate reduction for a safer, steadier drop
• Helps improve stability and reduce nuisance algae pressure
• Designed to avoid harsh swings when used correctly

Shop Nitrate Reducer

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