Oh no lol, it ain’t some naturally made pond and def not connected to other water ways, it was built and is for housing fish, I just don’t keep hard to maintain fish in there as sometimes I don’t have time to do weekly water changes and all.
So if tannins are not that good I’ll skip leaves as a full substrate then. Rocks I got, I think they would give a very nice natural look of a river bed as well, lots of rocks and sand in between.
but why is sand not that good as a full substrate fer marble cats?