Hi all, nice to meet you all - this is my first post on this forum

I have an existing 4ft x 1ft tank which is home to 15 albino corydoras (4 new eggs hatched in the last week - so its actually 19 now!).
It has pea gravel and is fairly heavily planted. It has a piece of bogwood, a large terracota plant pot and a decorative mug, where they can hide.
I have an external Fluval filter.

Id like to reinvent the tank for the Corys. Any suggestions or photos would be gratefully received! And HOW to do this also. I would like sand for starters and to recreate their natural environment as near as possible.

Thanks all xx