p. diffusa X harlequin rasboras

90%
Harlequin rasboras are some of the most ideal community tank members and should serve no problems to P. diffusa and vice versa. For temperature, they are quite compatible in a temperature within the range of 78-80F. For parameters, one should keep it at a stable 7.0-7.5, but both creatures should be able to tolerate up to 8.0. You do not want under 7.0 as that will cause the shell of P. diffusa to "melt". To keep these two together, a good beginner minimum would be a 15g standard.
[Seriously Fish|https://www.seriouslyfish.com/species/trigonostigma-heteromorpha]