I recently took my 6 year old Larius niger colony out of hibernation. I placed the ytong nest in a planted tank and will see this season how well it works. There is a chance that they will move into the substrate but it is OK. Here is a video of how I built the nest and set up the outworld.
https://youtu.be/C7Sude1-rKs
Nice video, thank you for sharing. I only wonder why the colony isn't bigger yet.
The colony is a few hundred or just over a thousand strong and not growing extremely fast. I caught several queens in 2012 and but kept 2. This one and one I gave to my sibling. The colony of the 2nd queen grew much faster than this one. It was at this size after 2 years. They were both kept in the same setup for the first 2 years with the only difference that my sibling's nest was in a much warmer climate and much shorter less severe winter. I think this could be one factor but feel that my queen is just a bit slower in general.