Looks like you are going through another mini cycle.
There was too much ammonia for the bacteria to absorb, so the excess ammoina is in the water column.
It should settle down after a few weeks - however monitor it closely. When the ammonia has gone from the water, you will need an ammonia source to keep the good bacteria alive (Fish, fish food, pure unscented ammonia).
- Planted CO2 Community Tank
- Planted Shrimp Tank - in progress