The other fish and shrimp require bubbler cause they need oxygen in water. African dwarf frogs do not. they breath air and love to make bubbles. I see bubbles at the tank edge which is a sign of happy frogs. I will stop rambling aquariums now I think I got it all out 🤣
Also some Molly's are bullies and like to nibble fins they could be bullying everyone. Especially when there are so many in a small tank. Just another idea. I only have 2 frogs and 2 loaches with few tiny snails and it's getting crowded as they have grown in 20 gallons. sorry I keep adding more...
I also never wait with an empty tank. I always just set up up after I'm home with the fish. I've had fish and aquariums for 25 years 😂 never have any die other than old age. But I have always stuck with fresh water.
Is there a lot of water movement with filter? Adf hate water movement. I've had my two about 3 years along with 2 loaches and some snails. I don't even have a filter. My plants filter it for me. I just add water each week that evaporated away