I performed a water change two days ago. My ammonia levels were at 0.25-0.5 ppm right after the water change, which one user suggested was due to the chloramine removers.
However, it has been two days and I saw one of my fish lying at the bottom of the tank, resting... during daylight. Its back fin is also tense, as in, it's not as big as it should be because he's contracting it out of stress. I tested for ammonia and it's at 0.5 ppm. My nitrates have increased to 10 ppm. I'm going to perform another 25% water change.
I added a carbon filter two days ago inside my AquaClear filter consisting of a one-month old bio-filter and a mechanical filter. WHY IS THIS NOT WORKING?
EDIT Just performed another water change, it definitely has to do with the de-chloramines. Maybe they aren't settled? What is the chemical reaction behind it?