My only problem with a sand bed so far was a nano with a 3 inch bed on a metal stand. There was no insulation beneath the tank. This was my first marine tank after years of freshwater, guy at the LFS thought it was the perfect setup: sand bed, no skimmer, no filtration, just a fuge and massive water changes. I think he estimated the amount of money I was comfy putting down and sold me what he could as an experiment... fortunately had an 80 already cycling and a 20 and 10 gallon quarantine going when it crashed. The sand got 10 degrees colder at the bottom when the room temp dropped to just over 60 degrees, and the stench was astonishing. Miraculously all coral and fish survived, I moved them immediately... a few went to the 80 which hadn't even started spiking ammonia and had $200 of uncycled liverock in it. I will never forget the smell.
All my tanks have substrate, I am not anti DSB or SB, just anti open stands with no insulation below the tank in a 60 degree room next to a drafty door with no filtration. That make sense? Am thinking of removing a lot of the sand from the 80 and using it to start yet another tank... I can really see now what benefits a system with no substrate offers as far as flow and nutrient export but keep the substrate as some of my fish either need it as a home or need the pods it harbors. I don't trust a fuge w/ DSB to be temperature stable as it has the same problems as the system placed on the metal stand.
Metal stands are great for potted plants.
Kate
