Wasn't sure which thread to post to as I believe they're really dealing with the same knowns and unknowns on the subject of substrate or no substrate.
I believe everyone who does or has kept a captive reef realizes there is no magic bullet. There's no magic in a bottle and there's no magic formula to the perfect reef tank. If there were, then someone would already be marketing it. If it were so easily repeatable, then it would be an off the shelf product. I think if everyone that's presently keeping a successful system (relative term by the way), would honestly have to admit that even if they duplicated their system down to the coral, things might not work out the same way in the duplicate tank. There are just too many variables. Duplicate conditions might be achievable in small controlled experiments in small containers, but when the system grows to larger scale, the variables multiply exponentially.
I understand the perspective of those from the BB side of the argument. If there's no substrate then one can clearly see there is no sediment and if there is, it can easily be removed. In re-establishing my system, I had this debate with myself repeatedly. My thoughts were, BB would be an easier system to maintain and thus, I'd be more inclined to follow through with easier maintenance rather than maintenance that took more effort.
At present , my system is cycling with a shallow sand bed of a mix of fine and special grade aragonite. My idea behind using the fine with the larger grain sand is the fine will act as a base and a binder for the larger grain sand, settling in between the larger grains like a loose bed mortar. Kind of how patio blocks might be set. I chose to have sand because I like the look of it vs a bare bottom. But, I also chose it because I believe there are benefits derived from it for the system. My hope is that the mix of fine and large grain sand will be a bit more dense and compacted and will not allow detritus to settle down into the bed and thus will not become the nutrient sink that many on the BB side believe it does become. I hope I made the better choice.
In many ways the choice was based on my prior experience in keeping a tank with corals. I had a 110g with a DSB and a plenum. It ran for almost ten years. It was my first and only tank, and being such there were certainly ups and downs as everything was a new learning experience and well this was back in the 80s and things in the hobby, as most of you know, were more unknown than they are now and that isn't saying much. I think the idea that this topic is still being debated is proof of that.
That system ran well and thrived. Corals grew and fish and shrimp even spawned in the system. I had a carpet anemone grow from 4" in diameter to almost 12". As Joe says he does, I used to make a storm in the tank, blowing the top of the sand only and all of the rocks, liberating detritus. So even in a BB tank, there is a buildup of detritus and if the keeper doesn't liberate it from the rock, well then "poo" or what ever organics that are particulate in nature, including the microfauna that have died within the rocks, will contribute to the bio load and build up even when water changes are performed. The nasty stuff has to be removed no matter what is or is not on the bottom.
Well that tank did eventually crash, but it was due to moving the tank and everything within and not handling the substrate properly. Back then the belief was keep the substrate as it is the biological filter. So I bagged it up like the rest of the livestock and reused it in the new location. I put everything back the way it was. Then we went on a 2 week vacation. Bad timing for that. I left a friend in charge and he had no experience nor any way of knowing if something was going wrong. Upon returning, I found the whole system in decline to the point it wasn't salvageable. That tank became a terrarium for a few years
What I find interesting in reading again about the hobby and in doing research is that little has changed on this front - the substrate argument. I read somewhere that many of the aquariums still utilize a plenum in their reef tanks. Can anyone verify this? If so, they are obviously well educated on what does and what doesn't work. Heck, maybe I should use a plenum :O LOL
Ah well, it's a rewarding hobby when things go well and it really sucks when it doesn't
Edit:
I was able to scrounge up one pic of my old 110g and scan it. It's the left side of the tank only, but it did look pretty
