Not sure what to tell you other than repeat your suggestion of video surveillance. Pretty sure the results might surprise a few people.
only the dwarf snake heads,the big ones can stay out of the country and go back where that belong.but i do like the pic,man i wish i could have one someday.
cherry barbs look nice i always see them at petco.i always want to take them home but then i remember i came here not for them.
hmm well you just basically threw my bn pleco idea out the door so..i dont know guppies?
I would go with dwarf cichlids as it is cool watching them care for the fry.
The Ph shouldn't matter that much. But Shell Dwellers would be good