This thread actually got me to register, so I could respond.
If it was just the Landlord, Iād say aquascape your till your heartās content.
However, you should work it out with your roommate, because civility is a lost art.
The real reason I wanted to resply to this is because of your hope to register the fish as emotional support animals.
Donāt get me wrong, you find fish tanks in doctor offices for a reason, and the calming effect of running water is proven to be beneficial to peopleās health, but clearly as this story shows, you arenāt suffering.
It is stories like this that has me wanting laws removed that protect emotional support animals.
Once your other roommate is onboard with the aquascape, buy some windup/remote control fish, and invite your landlord over.