Although I did not read Steve's work, I heard the story of how Steve was inspired to research cryptic zones and recalled his pile o' rubble sump back in 95 when I used to visit. (Steve that was a complement so don't blow me up
) Steve definitely had something going on in that tank that others could not seem to achieve. For whatever reason, I have always associated a good portion of that tank's success to that sump full of rock.
I am in the process of setting up a new tank and I wanted to incorporate a cryptic component to my sump. Reading this thread, I think I got most of the idea with the exception of the low flow part. I believe, however, that there will still be areas in the rubble pile that will not receive much flow. Hopefully it will be enough to achieve the goal. I invite Steve and others to comment.
The design is rather simple. I created a tower that will be filled with Tonga rubble. The walls of the fuge are smoked acrylic and the lid and back wall of the fuge are black acrylic to block out light. There are two perforated trays inside the fuge. The first one rests about 3" off the bottom. The second is 3" from the top and rests above the rubble pile. The tank overflow drain pipe runs through the rubble pile and lets out under the pile in the 3" gap between the bottom and first tray. Water must flow up through the pile in order to exit out the drain at the top of the tower. Hopefully there will not be so much bubbles and turbidity that it will inhibit cryptic sponge growth.
