Those guys from the picture beneath the window have a little firm for making and arranging aquariums. They are my friends so we made it together and it was a little bit cheaper.
I left a hole for the bulk 32mm, it is going to be used for water changes. When I open the valve 35% of the water drains. No more buckets and wet floor
For substrate I used potting soil mixed with some iron suplementation. On top of it I put quartz sand granulation 1-3mm.
Potting soil was sunken for 3 weeks, then it was dried and sunken again.