Thanks for the feedback.Originally Posted by ILLUSN
To answer your questions with such a small aquarium we didn`t want to lose too much water to the substrate. There is a slow migration of water through the foam base plate preventing anaerobic gas formulation. Its only a saving of 5 liters but it counts when its 5% volume.
That is exactly how we built the cave. Since the tank has been running I havent seen any exposed foam. I use this method in all of my showtanks to great effect.
We have a had a recent earthquake that shifted the cave slightly. (It also dropped 300l or so on the hatchery floor, and broke a thermometer.-we were very lucky.)