Thank you Peter and Helene for your fast response!
I did forget to say that the tank will be a display tank.
So i realy want some plants in it and a substrate for the plants ( to cover to bottom to ), with on the substrate some leaves ofcours. Did find a small list of plants that are used in Borneo blackwater biotope tank.
microsorium pteropus
crypto soorten
Hydrilla verticillata
Limnophila sessiliflora
Najas indica
Blyxa aubertii
Blyxa japonica
Hygrophila polysperma
Hygrophila corymbosa
Nymphaea stellata
Salvina natans
Javamos
About the Hang-on filter that comes with the fluval edge 46L, it has a flowrate from 378 l/h Max – 125 l/h Minimal. So I did calculate it and thats a 2.7 of the total volume of the tank. As far as I know isn´t that to much in this matter (if i´m correct). While it only cycles on peat and filtation media.
Did look up the Fluval shrimp stratum and it sounds very good for using, it keeps the PH low, is good for planted tanks and looks good on the bottom (nice tip).