I am fairly new here and have been doing a ton of research. Recently I have been trying to learn more about the role the sandbed plays in the reef ecosystem and I have a few questions I haven’t been able to find.
At first I thought that the reason you didn’t want to stir or “disturb” your sandbed was because there were anaerobic bacteria living deep in the sandbed that were helping breakdown the nitrate in my tank and stirring would maybe kill them or at least keep them from doing an important/helpful job? Then I heard the reason was because there could be lots of nitrates and possible hydrogen sulfide trapped in there and you just didn’t want to release it, at least not all at once.
I have also read about the sand stirring from day one and never letting those harmful substances build up.
I think I would like to go the route of stirring regularly, but as my tank is only 6 weeks old I want to make sure I’m not inhibiting the growth of some beneficial bacteria by starting this.
I just don’t know about all this. When you say sandbed, do you mean 8-9+ inches deep or 3-4 inches deep?
I have always ran sand beds. Some for 5+ years. I aim for 3-4” deep but end up with places that around 1” and places that are around 4”. Sometimes as deep as 6”. I think they make things look more natural, add a ton of filtration, expand your options for fish, create a natural habitat for a lot of organisms, and with the right color, help reflect light back to coral.
I stir up my sand bed or move a rock when I think about it- once every 1-3 months. I also rake my sand back into place with my tiny zen garden rake weekly. Every year I replace about 10-20lbs (or around 10-20%). I have seen the little bubbles of supposed death in it. As you look through the glass you can see the layers of black and red and the tunnels of worms and things running through it. It’s very much alive and teeming with life. But it has yet to murder or even cause a ripple.
I have never once had any issues with deadly gas- including stirring the sand bed and seeing bubbles rise to the surface or watching a hermit crab slide across the sand while tiny bubbles pop up behind him and rise to the surface (maybe it’s something he ate?) Anecdotally I have never heard a story of “I mixed my sand bed and everything died!” first hand. You can post the usual “one time I read that my friend stirred his sand bed and then the next day his dog died!!” but without being there and understanding the tank, it’s correlation vs causation or freak incidents at best.
I think (and I stress “think”) that back in the old days people ran sand beds of 8, 12, maybe more inches deep. At those depths you may be creating dangerous situations but no one really does this anymore in their display unless they’re growing garden eels or something. 3-4” with nassarius snails, gobies, and just general maintenance offer enough agitation to mitigate any issues.
It has come into favor to use no sand. You’ll see a lot of proponents for that. That’s fine. What’s less ok is that in the past few years there’s a sentiment that it’s “better.” It isn’t better or worse, it’s a personal choice. Bare bottom is Easier to clean and Easier to direct flow. Maybe a little more difficult to start up and stabilize unless you know what you’re doing and are using other systems.
Sand beds of a few inches and up to 5-6” create a massive amount of filtration that many new hobbyists can use to be successful. They provide a cushion and buffer to mitigate and lessen the impact of new tank errors. The cost is some extra maintenance.
Just like biopellets, carbon dosing, zeovit, algae scrubbers, refugiums, AWC’s, protein skimmers, live rock, denitrifying chambers, ozone, cryptic zones, remote deep sand beds, deep sand beds, fluidized sand beds, , etc there are sooo many different systems and tools to pick and choose from to find success. You have to pick the ones that fit into your life, your space, and your budget
As an analogy: You could say an automatic transmission is “better” than a manual transmission but some people love the control, the physical interaction, and the connection with the car a manual provides.
I will leave by saying that removing an active and mature sand bed is a really bad idea. You’re removing, in many cases, your main source of filtration in your tank. Your tank will “cycle” again as it attempts to create equilibrium. Screw what evil gasses are hiding, removing the majority of the bacteria and surface area for them to dwell on from your tank will definitely cause problems. Adding a sand bed, while messy, is completely possible.
