A clearly well researched tank.
What substrate is that?
The lava rock whilest I would not use it, should be no prob as there is only one lump.
Sex mix of the dubs may be a problem later unless you have selected more females than males.
4 Eretmodus Cyanostictus will prob not last unless you are lucky or have selected 1 male and 3 female.
chuck the plecos they will eat your algae which is what helps keep your other fish healthy.
Clean your own front glass :wink: .
Good luck.