deep sand bed cover image

Are deep sand beds just a thing of the past?

When I started in the hobby, deep sand beds were trending towards the end of being in vogue…that is, I guess if one could ever consider deep sand beds to ever have been in vogue. As a side note here, I don’t think I’ve ever used the phrase in vogue before, but now I’ve done it three times in the span of 60 words, but I digress.

At the moment, I’m feeling like one of those old guys clinging on to the way things used to be, wondering, are deep sand beds just a thing of the past?

I wonder if I’m the only one left in the hobby with a tank that has a deep sand bed.

Advantages of deep sand beds

From my perspective, a deep sand bed carries a few advantages over a bare bottom tank.

Water purification advantages

From a water chemistry and purification perspective, what I love, love, love about my deep sand bed is that there is a ton of surface area for both aerobic and anaerobic bacteria to live and grow. Those bacteria turn ammonia into nitrite and nitrite into nitrate, essentially becoming a fantastic live sand.

“But Al,” you’re about to say, “the bacteria in my tank do the same thing, and I don’t have a deep sand bed.”

Very true, but allow me to finish. Deep within my sand bed are anaerobic bacteria—bacteria that grow only in the absence of oxygen. Those bacteria actually remove nitrate from the water.

My deep sand bed acts as another living water purification system and helps clean my water for me.

Aesthetic/Interest advantages of deep sand beds

In addition to the functional benefits to water chemistry just described, here is another reason I love my deep sand bed:

deep sand bed 2

Critters. Yup. Critters. All sorts of critters. Green stuff, brown stuff, little worms, little pods. One of my favorite things to do is take a look at my sand bed at night to see what’s moving around down there. I don’t know exactly what all that marine life does…but I have to think they’re also turning one sort of waste product in my tank into their food and processing it for me.

engineer goby

Engineer gobies need a deep sand bed to burrow in

Last, but not least, my deep sand bed is home to some other pretty fun animals—my burrowing fishes. At different points in time, I’ve kept jawfish and engineer gobies, which are fascinating to watch. The gobies seem to never stop building, and the jawfishes are just amusing to watch, as they bob up and down, afraid of their own shadows.

yellow headed jawfish

The downsides to having a deep sand bed

At one point, I did lose some coral tissue (not the whole animal), because a goby pair insisted on burying it, day after day until I moved it far enough up.

The sand does get dirty, from time to time. If you’re a complete neat-freak that has a low tolerance for any brown stuff in the tank, this might not be the look for you.

Last, but not least, is something I haven’t seen written about in a long time, probably because not a lot is written about deep sand beds these days—but the older literature talks about a risk of old tank syndrome or the leaching of toxic chemicals from that anaerobic part of the bed that I’m oh, so proud of.

I’m not sure if it’s the diggers that have kept me in the safe zone, just dumb luck, or if a tank catastrophe is about to happen at any moment (no doubt accelerated here by ‘jinxing’ it and writing about it right now), but the fact remains that my current tank has been running for somewhere around 8-9 years, at this point, with a deep sand bed, and it’s as alive and vibrant as ever.

deep sand bed cover image

I guess I’m a bit old school. I’ve certainly always been stubborn, but I love my deep sand bed and I’m convinced it provides a level of biological filtration and stability that allows me to be a little more laid back about all the maintenance.

Am I the only one out there? Let me know what type of sand bed you have with a comment below.

Comments

  1. I plan on doing a deep same bed in my 140gl. My question is how deep are week talking about here? 4 inchs plus or more. Also planning on making my own life rock with pedistal bases so they will not sink in to the sand from burrowing critters! Maybe we could see a topic on making live rock?

  2. I had a deep sand bed set up for 18 years. All life that I introduced to this mature reaf flourished and gave me a lot of pleasure. Regretably I followed the trend and shifted to the new way of filtration because it seamed to be the natural way to go. I have been planning to return to the old ways for some weeks now. It is happening, thanks for the nudge.

  3. My deep sand bed was black and lasted about 10 years before nuking my tank. I was able to save some fish and mushrooms.

    The black sand had metallic pieces in it and my magnet would catch them and scratch my glass.

    Now I keep a shallow sand bed and stir it somewhere daily. Pillow floss catches the waste rather well. I change it twice a week.

  4. I just simply love the look of a deep sand bed. I think my sandbed would be considered deep, probably not as deep as yours since I have only been in saltwater aquarium keeping for over a year. I do have a deep rock bed in the freshwater, but I have had it for more than 5 years.

    Again, it is the look (wink)!

  5. Author

    Brandon, thanks for the comment/question. Yes, traditionally 4+ inches and there are reports (most of the info I’m aware of is older at this point). There is some reason to use caution that in between depths may not properly separate the aerobic from anaerobic bacteria–they’re deep enough for the processes to get started but not deep enough to avoid being disrupted… and if you disrupt you do run the risks of harmful gases escaping into your water. So I think the older advice is to try to achieve 6 inches, to give yourself a little wiggle room. I can’t say I can back all this up scientifically. I encourage you do so some more research. I will try too.

  6. Author

    Bernie,

    Thanks for the comment. I was glad that I ‘rebuilt’ once after going bare bottom and I don’t regret going back :). Glad to see another kindred spirit there.

  7. Author

    Yvonne,

    Thanks for the great comment, as always. I think you bring up a few important counterpoints to my one-sided love-fest for DSBs. Your black sand had metallic pieces which were attracted to the glass cleaner magnet and scratch the glass. That is certainly a risk. I know my MagFloat gets sand in it and scratches things up occasionally. So that is definitely a good one for the ‘cons’ column. As far as nuking the tank–I had read about that happening, as the beds get older–but I have also read about old tank syndrome as a concept that doesn’t necessarily involve a DSB. So for me, having never experienced it, I was neutral on the topic. thank you for sharing your experience there.

  8. Author

    Angelann,

    Thanks for the comment. I also do enjoy the look of a DSB…and staring at it to find cool little things. Have you thought about adding more sand to your bed to make it deeper? You’d have to move your rocks and corals up…and it would make a mess for a few days…but you could do it, if you really wanted the look.

  9. Do sand beds need to be cleaned, vacuumed, occasionally? How is that done with live rock taking up a bunch of floor space? I am afraid of disrupting the many corals on the rocks if I need to move them but, after 3 years without vacuuming, though my tank looks healthy, I am afraid of a crash.

  10. Author

    Hi Mike,

    Thanks for the question. I don’t do a ton of vacuuming. When I do partial water changes, I do occasionally vacuum the top layer, if there is obvious detritus. Otherwise, I just let it go. My engineer gobies do stir up the sand. They seem to love it and are constantly moving sand around and they actually prefer to dig under the rocks. In the past, I’ve gone ~2 years without any sand-stirring creatures and then added new ones and have had no problems. Creatures I’ve had that naturally disturbed the sand are engineer goby or a jawfish, or even nassarius snails.

    There are a few very scary threads floating about the internet that talk of hydrogen sulfide poisoning from disturbing those lower layers of the tank and talks of the sandbed wiping out older tanks. I’m not convinced that the evidence points to the sand bed as the culprit. In fact, most of the threads don’t really have much evidence at all, besides the fact that the tank did crash. Which is terrible…and I do suppose it’s possible…but even if possible…likely very rare.

    What I can share with you is that I’ve had a deep sand bed (fine sand) in my tanks for years. I’ve had my current tank set up since ~2009 or 2010 and the sandbed has been there continuously. I have no sand-stirring method other than keeping engineer gobies for probably 6 of the 8-9 years.

    At one point, there was a power failure for several days and when I started things back up, I lost a lot of things–but there was a lot going on then. Massive temperature changes, oxygen level changes, water movement changes and I’m sure a lot of invertebrate and bacterial life lost. I don’t own a hydrogen sulfide test, so I can’t rule out that was an issue at that time, but I think the more obvious culprits were stress and biological filtration loss as a chain reaction.

    I haven’t seen any scientific or rigorously explored articles or experiments that truly demonstrate true issues with deep sand beds. Just threads from hobbyists blaming the bed for their crash and jumping on the hydrogen sulfide witch hunt (without documenting evidence).

    At this point, now that you’re three years in, I’m not sure what advice to give you. My gut says to start with small diggers (like burrowing snails) and then consider adding an engineer–if you believe the engineer will be smart enough to not poison itself through digging. I also have read an article stating that sand beds likely don’t have the capability to develop toxic levels of sulfide. He calls the hydrogen sulfide and need for sifting thing to be ‘imaginary problems.’

    Long comment…short…I think you’re going to be okay here.

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