Confirm and trace the reading
Repeat the test with a clean vial and check nitrite as well. Look for uneaten food, dead animals, clogged media, or a filter that stopped running.
A tank can appear cycled before it has demonstrated that it can handle the actual waste load. Adding shrimp may reveal that gap.
Respond with a measured plan
Maintain aeration and ask an experienced keeper to review the tank volume, readings, and source water if ammonia is confirmed. Use compatible replacement water for any change.
Do not wash or replace all biological media. Feed lightly and keep testing until the filter reliably processes waste again.
For your own tank
Do not rinse the filter under untreated tap water while trying to fix the spike. Maintain aeration, remove decaying material, and follow a measured response based on the actual test. Continue testing until the biological filter is stable again.
- Aquarium Co-Op · The Beginner's Guide to the Nitrogen Cycle
- Aquarium Co-Op · Care Guide for Cherry Shrimp
Use these as general hobby references. Test your aquarium and confirm product guidance before making changes.