I’ve always used chicken grit (#2) for my ballast. But I’m trying to find something that looks the same but isn’t as heavy. Has anyone found a passable substitute?
Jon.
Cheap kitty litter. Takes paint well, too.
Dried, used coffee grounds work well, too.
That might be an excellent idea Steve. I never thought about the kitty litter. We probably have some in the garage (we use it as floor dry).
Jon.
You just have to train the kitty to stay off the layout. 
My son reminded me today that we had a litter of kittens in the garage this past fall… We’ll be stopping at the store in the morning for a fresh bag of kitty litter. 
In my previous small scale (H0) life, I used some dried coffee grounds for ground cover. Within a short time they had absorbed enough moisture from the air to turn everything in the area into a green rotting mess. Very difficult to clean up!
Happy RRing,
Jerry