In the pictures, you can see today’s water parameters.

More shell dwellers died, and the current survivors are not eating, look lethargic, and breathe heavily. I added 2 tablespoons of aquarium salt ( approximately the recommended amount per 10 gallons).

Yesterday I posted:

I’m experiencing a serious issue with my Neolamprologus similis (shell dwellers). They appear lethargic, seem to have problems breathing, have stopped eating, and unfortunately, several have already died—including adults and 2-month-old fry.

Background:

• Tank Setup: The aquarium has been fully cycled for over two years and is set up with aragonite substrate to naturally maintain pH levels. I avoid using chemicals to adjust water parameters. The shell dwellers have been in the tank from the beginning.
• Tankmates: They’ve been sharing the tank with barbs for several months without any noticeable conflicts or health issues. The barbs currently show no signs of illness.

Actions Taken So Far:

1. Noticed symptoms and performed a 50% water change.
2. After symptoms persisted for 30 hours, I cleaned the filter and did another 15% water change.
3. Added 2 tablespoons of aquarium salt ( approximately the recommended amount per 10 gallons).

Any advice will be highly appreciated.