How to Set Up and Read the Seachem Alert Combo

By Pro Shrimp | Published: 2026-10-31

Category: How-to Guides

Learn where to place the Seachem Alert Combo, how to read the pH and ammonia color alerts, and the common mistakes that cause false readings.

Quick answer

Place the Seachem pH Alert and Ammonia Alert in a high-flow area of your aquarium or filter, wait for the colors to stabilize, and compare them to the printed reference card. Treat any color shift as a prompt to confirm with a liquid test kit before acting.

Why continuous monitoring changes your routine

The Seachem Alert Combo is not a replacement for periodic liquid testing. It is a continuous visual check that shows you when pH or ammonia starts to move, so you can test and respond before fish show stress. Use it as an early-warning layer, not a precision instrument.

Because the sensors change color reversibly, they can return to normal if a spike passes. That is useful for catching transient ammonia events, but it also means you should not rely on the badge alone to confirm that a problem is gone.

Placement trade-offs that affect accuracy

The most common mistake is placing the devices in a quiet corner or behind hardscape where water movement is low. The sensor needs flow across its surface to reflect the surrounding water. A filter outlet or an open area with gentle current is usually better than a still dead zone.

Avoid placing the badges where they will be knocked, covered in algae, or exposed to air during water changes. If the sensor dries out or gets coated, the color can mislead you. Keep them visible and easy to remove for cleaning.

Setup steps and checkpoints

Unpack and record the reference colors: Before placing the devices in water, compare the sensor colors to the printed reference card and note the starting colors. This gives you a baseline for later comparison. If the colors already look off before use, check the packaging date or return the unit.
Choose a high-flow location: Place both the pH Alert and Ammonia Alert in an area with steady water movement, such as near a filter outlet or in the main tank flow. Avoid dead spots, direct air bubbles, and areas where fish can knock them loose. If you cannot find flow, aim the filter outlet toward the badge rather than moving the badge into a quiet corner.
Mount securely and keep the sensor visible: Use the supplied suction cup or holder to fix each device at a readable angle. Make sure the sensor surface faces the water flow and is not shaded by plants or hardscape. Recheck the mount after water changes or maintenance; a fallen badge can sit in still water and read incorrectly.
Wait for stabilization before reading: Allow the devices to sit in the water for the time stated in the instructions, then read the color under consistent lighting. Compare the sensor color to the reference card, not to your memory. Read at the same time of day with the same light source to avoid apparent shifts caused by lighting.
Respond to an ammonia warning with a confirmatory test: If the Ammonia Alert shows a color shift toward warning, test the water with a liquid ammonia kit and check for causes such as overfeeding, a dead fish, or a filter disturbance. Do not dose chemicals based on the badge alone. A badge that returns to safe color does not prove the ammonia is gone; confirm with a test before assuming the event has passed.
Clean the sensors without scratching them: If algae or biofilm dulls the sensor, remove the device and gently wipe the sensor surface with a soft, damp cloth. Do not use abrasive pads or solvents. Clean when you notice a color that does not match your liquid test results, not on a fixed schedule.

Product facts

Seachem Alert Combo pH & Ammonia: The pH Alert sensor changes color reversibly between pH 5.4 and 8.0, and the pack includes both pH and Ammonia Alert devices. This gives you a continuous visual range for freshwater pH and ammonia without strips, but you still need a test kit for exact values outside that range.
Seachem Alert Combo pH & Ammonia