seachem prime
Seachem Prime
What is Seachem Prime?
Prime® is Seachem’s flagship complete and concentrated conditioner for aquarium water preparation. It instantly eliminates chlorine and chloramine, then binds ammonia, nitrite and nitrate into a non-toxic form that remains bio-available to the filter bacteria—protecting livestock while still allowing the nitrogen cycle to function.
Why choose Prime over regular dechlorinators?
5 × more concentrated than most competing products—smaller bottle, lower cost per treat.
Multi-pronged protection: detoxifies heavy metals commonly found in tap water.
Reef-safe & non-acidic – won’t shift pH or over-activate protein skimmers, so it’s trusted from nano tanks to coral reefs.
Versatile use-cases – start-ups, water-changes, fish transport, quarantine, or emergency ammonia/nitrite spikes.
Broad size range – 50 mL pocket bottle up to 1 L economy jug (larger trade sizes also available).
How it works
Prime reduces toxic dissolved chlorine gas (Cl₂) to harmless chloride ions, splits chloramine and immediately binds the liberated ammonia, preventing gill burn while beneficial bacteria consume it. The same binding mechanism temporarily renders nitrite and nitrate safe, giving your bio-filter time to catch up.
Dosage & directions
Standard dose: 1 capful (5 mL) per 200 L / 50 US gal of new water.
For high chloramine, double the dose; for emergency ammonia/nitrite detox, up to 5× the standard dose is safe.
If water temperature exceeds 30 °C (86 °F) and chlorine/ammonia levels are low, use a half-dose.
Prime may be added directly to the aquarium, but best practice is to treat make-up water first. The characteristic sulfur smell is normal.
Sizes & coverage

*Based on standard 5 mL / 200 L dose.
FAQs
Will Prime stall my bio-filter? No—ammonia remains bio-available while harmless to fish.
Can I overdose? Up to 5× the normal dose is routinely used in emergencies without harm.