[datfish]

I'm going to be mixing soil with red clay and some sand, then doing a layer of leaf litter and other dried botanicals.

Any suggestions for other materials to add?

 

[sysyhus]

Why is the clay red? iron content? What is the purpose for the clay? Mixing clay with soil then adding water I could see turning out to be a sloppy mess. Add peat to the filtration system if you trying to go blackwater.

 

[hp10BII]

Did something similar in a Borneo biotope a few years back focusing on loaches. Instead of red based or clay mixture, I used 3M tan coloured quartz sand for substrate. Very easy to keep clean.

I like this for ideas:

BIOTOPE AQUARIUM DESIGN CONTEST 2016 - Biotope Aquarium