I quickly set up a hardscape-only aquarium using a dead pinus sylvestris bonsai, some petrified wood

I quickly set up a hardscape-only aquarium using a dead pinus sylvestris bonsai, some petrified wood and sand. It is primarily for testing if (and how) such a setup can be kept clean. These look super-simple, but I am afraid they are not :) We’ll see, this is Day 0, or rather Hour1. It is a 54l tank, inhabited by a school of 15 rasbora kubotai.