Ammonia in an Aquarium – Immediate Water Checks

What to check first

• Perform an appropriate partial water change.
• Condition replacement tap water and increase aeration.
• Confirm the filter is working and retest after corrective action.

What you can do now

• Perform an appropriate partial water change.
• Condition replacement tap water.
• Increase aeration.
• Check whether the filter is running normally.
• Remove uneaten food and obvious decaying material.
• Reduce feeding temporarily.
• Do not replace all biological filter media at once.
• Test again after corrective action.

What may be contributing

• An immature or disrupted biological filter
• Excess feeding, stocking or decaying material
• Reduced filter operation

Questions that help narrow the problem

Are fish gasping, very inactive or otherwise distressed?

Yes · No · Not sure

Is the filter running, and was it recently cleaned or changed?

Running normally / no recent change · Recently cleaned or media changed · Stopped or not working normally · Not sure

Would you like to enter the exact ammonia and other water-test results?

Yes · No

Relevant tests and product guidance

These links come from the existing troubleshooting record. They do not replace water-quality correction or the current product label.

• API Ammonia Test Kit
• API Nitrite NO2 Test Kit
• API Ammo Lock
• API Aqua Essential
• Seachem Prime
• Seachem Stability
• API Stress Zyme

Avoid for now

• Do not treat an ammonia-binding conditioner as a replacement for correcting the underlying aquarium problem.
• Avoid replacing all biological media.
• Avoid continued heavy feeding.