When experiencing sudden nitrite (
NO2) reading, it could be for few reasons
All Ican think of is the following at this moment.
1.
pH has dropped/dropping too low.
2. Test vial was contaminated (not thoroughly rinsed)
3. Experienced sudden surge of Ammonia (
NH3) recently?
4. Aeaerobic bacteria (dead zone) is developed (maybe since s/w, under the rocks)
5. Tap water has NO2?
You may have ran few test already but if have not, run another test using clean vial.
Edited since S/W.
If you are using liquid test kit for S/W and experiencing what may seem false readings then get powder Test kit where reagents are packed in aluminum foil w/ expiration date.
I dont know the age of tank or
LR but it could be things dieing off or foods decaying under the LR.
1. Do a test on tap for NO2, then add single drop of Stresscoat+ to same vial and let it sit to see if color changes
2. Do nitrite test of tank water and add single drop of stresscoat+ to same vial to see if color darkens.
Sugar can be utilized as C source in
denitrification process but dont add to the tank. It is too expensive for that purpose. I am sure sugar is not added to Marsh to process anaerobic activities.
btw, nice angel and trigger.