good idea I did not know fish did that when they are gonna die...
(although it does not surprise me much)
I think I am just going to start out a little more simple now.
I still want to have some cave action for my fishes, but I was thinking about how I would have to take it apart and drain it somehow everytime I needed to clean the gravel really good. I am going to start out with something more along the lines of what you have done.
but, I still am drawing up some more plans, I will maybe just stack them atop eachother biggest on bottom and smaller as I go up... anyway, thank you for that warning. :worthy: