u/Embarrassed-Sky-5530

I posted previously about needing help with regulating the tank parameters and people asked for pictures, it wouldn’t allow me to post in comments so I made a new post! Long story short plants are thriving, animals dying (except octo and tiny snails) seems like the general consensus was to get a API testing kit for more accurate readings any other tips?

Need help find solutions to regulate levels in this tank (newer to fish)