MartyMA
Aquarium Advice Activist
Tank is a 40g breeder
Ph is about 7.4
Ammonia/nitrite are 0
Nitrate falls between 20 and 40
Bottom feeders are 2 juvenile clown loaches (list the 3rd some time ago).
Filter is a Marineland c-360
It's a planted tank. Was thick at the time of mystery 1. Not as thick now.
Only other tank mates are 1 young angel, some danios and mollys. I have several otos and some SAEs, too.
I have panduros and have kept other dwarf SA cichlids in the past. Even though small, they are quarrelsome. I would keep only one kind together myself but with enough space, you should be able to manage. If you sit and observe them interacting, it is easy to see how they are going to sort themselves out. You did not mention your water hardness. You might want to test gH and kH hardness. Most of the dwarfs prefer fairly soft water acidic water. Your pH is okay but closer to 7.0 and lower would be better. You might want to rearrange your tank to create distinct areas and break up sight lines at the same time. Rethink the rock decorations by replacing with driftwood. More natural and will help get your water closer to neutral. This is just my opinions, not a rules.
So, what happened? A male panduro started to do what he likes to do...beat up everyone else. Your other fish cleaned up after.