• Seachem sensor technology.
• Continuously detects and monitors free ammonia.
• No test kits, chemicals, or procedures are needed. Just constant readings.
• Lasts over a year.
• Marine and freshwater.

Ammonia Alert is an innovative color device for continuously detecting and monitoring toxic free ammonia. A sensor changes reversibly from yellow to green to blue, relative to the ammonia concentration. No test kits, chemicals, or procedures are needed. The device detects less than 0.05 mg/L (ppm) free ammonia and alerts you to the #1 killer before any sign of stress. It lasts over a year. This product is not recommended for use at acid pH. Marine or freshwater use.

In the absence of free ammonia the unit will assume a yellow or faint yellow-green color. It is normal for the dry sensor to have a greenish hue. It may take up to a few days for a dry sensor to equilibrate with the water. No sampling of water, chemicals, or test procedures are required. The presence of the free ammonia is detectable continuously with a response time of about 15 minutes. Response to decreasing ammonia is slower, requiring about 4 hours to go from TOXIC to SAFE on removal of ammonia.

How to Use

Peel the backing and stick the sensor inside the aquarium where you can see it, below the water line and out of direct flow from a return. No reagents, no procedure, no sample — it reads continuously from then on.

Compare the sensor’s colour against the printed disc: yellow means safe, green is ALERT at about 0.05 mg/l, and blue is ALARM at 0.2 mg/l rising to TOXIC at 0.5 mg/l. ALERT is tolerated for three to five days, ALARM for one to three, and TOXIC needs action immediately.

It responds to rising ammonia within about 15 minutes. Falling ammonia is slower — allow about 4 hours to return from TOXIC to SAFE after the cause is dealt with, so do not judge a water change by the sensor in the first hour.

What’s in the Box

One Ammonia Alert sensor with the colour reference disc printed on it, ready to use.

Service Life

About one year of continuous use, after which the sensor should be replaced.

It detects free ammonia (NH₃) — the toxic form — below 0.05 mg/l. That is a different measurement from a total-ammonia test kit, and it is the one that matters for the fish: ammonium is comparatively harmless, and how much of your total ammonia is in the free form depends on pH and temperature. This tells you when to act; a test kit tells you how much is there.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.