A few days ago I added a sand substrate to my 5ft tank and the fish LOOOved it! They were all so happy digging away and doing the fish versions of snow angels. Fish made hills and valleys appeared overnight and I was happy because they were happy. Last night when I fed the fish I noticed one of them taking a particular intrest in a flowerpot cave, entering and exiting. This was strange as usually any fish entering would be chased out by the male bristlenose who lives there. I looked in the pot but no one was home, I located the female bristlenose safe under some wood but then found the male dead under a rock. He had dug up the sand to get under the rock, with little support it had then shifted position pinning the BN underneath. I just wanted to warn people that this kind of thing can easily happen, I'm going to make doubly sure from now on that all of my hardscape is supported by the base of the tank and not just the substrate. Its a bit more effort and makes your layout less flexible but if its going to help save lives then it's worth it.
Also lost my male Kribensis today, his mate chased him to death leaving around 60 fry fatherless