You have to find the root of the issue.
Are you using RO/DI water?
Have you always used RO/Di water?
How much are you feeding?
What are you feeding?
What have you added lately?
come back.
I do use RO/DI water.
I feed every other day. It's usually flake food. once a week I use frozen brine shrimp.
I've added some snails and also some crabs but that's really about it.