Seachem AmGuard

SeachemAmGuardis a fast-acting liquid ammonia detoxifier for freshwater and saltwater aquariums. One dose neutralizesfree ammonia(NH3) and ammonium (NH4+) within minutes and stays active for up to72 hours, twice as long as most competitors. AmGuard converts ammonia to a non-toxic form that your biofilter can still consume, so it is safe to use during cycling, after a fish-in emergency, or as a precaution before water changes.

Pair AmGuard with Seachem Prime for dechlorination, an ammonia test kit to verify zero readings, and our full additives and supplements collection for a complete water-care kit.

Features

• Detoxifies free ammoniawithin minutes and holds for up to 72 hours
• Safe duringtank cycling, biofilter can still consume the converted ammonia
• Doesnot alter pH
• Works infreshwater and saltwater
• Available in three sizes for nano tanks up to large systems
• Reef and inverteb safe at recommended dose

Choose Your Size

Size	Best For	Treats Up To
100 mL	Nano and small tanks, occasional emergency use	~2,640 gallons total at the standard dose
250 mL	Mid-size single tank, regular hobbyist use	~6,600 gallons total at the standard dose
500 mL	Multi-tank fishrooms, breeders, reef systems, best value per ounce	~13,200 gallons total at the standard dose

Dosing

• Standard dose:1 mL per 40 L (about 10.5 US gallons). One dose neutralizes up to 1 ppm of free ammonia.
• Emergency dose:up to 2x the standard dose for ammonia spikes (max 2 mL per 40 L).
• Dose directly into the tank or sump where flow is good. Effect is rapid.
• Re-dose every 48 to 72 hours until ammonia readings stay at zero on a free-ammonia test.

Specifications

Brand	Seachem
Product	AmGuard
Type	Liquid ammonia detoxifier
Available Sizes	100 mL, 250 mL, 500 mL
Water Type	Freshwater & Saltwater
Affects pH	No
Reef Safe	Yes, at recommended dose
Origin	USA

Recommended Pairings

• Seachem Prime for dechlorinating new water during changes
• Fritz Ammonia Test Strips for fast tank-side checks
• Seachem Alerts continuous in-tank ammonia and pH badges
• Full water testing collection to round out your kit

FAQ

How is AmGuard different from Seachem Prime?
Prime is an all-in-one water conditioner that handles chlorine, chloramine, and modest ammonia spikes for about 24 to 48 hours.AmGuardis a dedicated, longer-acting (up to 72 hours) ammonia detoxifier with no dechlorinator. Use Prime for routine water changes and AmGuard for sustained ammonia control during cycling or an emergency.

Is AmGuard safe for reef tanks?
Yes, AmGuard is reef-safe at the recommended dose. As with any treatment, start at the lower dose and observe sensitive coral and invertebrates.

Can I use AmGuard during a new tank cycle?
Yes. AmGuard converts free ammonia to a non-toxic form that nitrifying bacteria can still consume, so it protects fish without stalling the cycle.

Will it interfere with my test kit?
A total-ammonia test (such as the Nessler or salicylate type) may still read ammonia after dosing because both free and bound ammonia are detected. Use a free-ammonia or NH3-specific test to confirm AmGuard has done its job.