OOOOOHHHH Zen Garden------keeeuuuuwwweeeeelll!!! (Pan: malawis meditating in their garden) Thanks for all the pix!
As for the marbles: I'm using the flat melted large marbles in my 10g for now, and using a gravel vac does great, just kind of push them around. Levels stay pretty steady, just don't overfeed, and catch any plant matter if it's there!!
CONCERN: any kind of (new) plastics "outgass"--could this possibly create a harmful chemical release into the water which isn't picked up by the test kits? Jes' wundrin', cuz they look fun for the fish.
--r