Equipment
Feb 22, 2026
Why Is My ORP Low Even When My Reef Tank Looks Clean?
Quick Answer
Low ORP can come from dissolved organics, low gas exchange, or probe drift. Clean and calibrate your probe before making big changes.
A visually clean tank can still have a lower ORP reading.
- Organic load from food, coral slime, and fish waste can depress ORP.
- Poor surface agitation or high indoor CO2 reduces oxidation potential.
- Old ORP probes often read low if not cleaned and calibrated.
Start by cleaning the probe, improving aeration, and maintaining stable export (skimmer, carbon, water changes). Shop for oxygenation and filtration upgrades at /shop and monitor trends in the ReefBay app.
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