Deep Sand Bed vs. Shallow Sand Bed

Hey Everyone,

I was just wondering what's the advantages and disadvantages of a DSB and a SSB?

I have a 72 gal. bowfront but I dont know if I want to go dsb or ssb, I'll decide on which looks better.

If I want to go dsb, how much sand would I need? In contrast, in ssb how much sand is needed for a 72 gal. bow? Is there a general rule?

Also can I get suggestions to the type of sand to use, name of the sand and brand, the colors (black, pink, white, etc.) and what the differences each color has, and what size grain sand is best to use?

Thanks everyone.

 

SSB, you can use like a bag for. It's really for decoration; most fish will be ok with it, but some fish like to have the DSB to dive into or burrow in, like wrasses, jawfish, dartfish, and some gobies. Some inverts might need deeper sand too, like nassarius snails, sand sifting stars, and some pistol shrimp.

DSB, you need at least 3-4 inches. It'll remove some nitrates, and satisfy those kinds of fish and inverts. It can't be disturbed too much, or you can have pockets of chemicals released into the tank that'll cause some mayhem.

 

Pretty good synopsis by Blackraven.

There is a heavy debate over the ins and outs of DSB's... I have gone with a DSB (approx 4-5"). But because nitrate reduction techniques are getting to be a lot better through other means and a DSB DOES have limitations and downsides, I may have gone slightly less (2-3") if I started over...

I think that the biggest factor would be as to what kind of critters you want to keep. If you keep something that requires a DSB, then there you go.

Also, some folks have gotten good results that remote DSB's may work pretty good for nitrate reduction.

 

One thing about DSB is that nitrate removal only happens at the barrier between anoxic and oxygenated water and not in the fully-anoxic area, so you don't need to have it as deep as people used to make them.

 

the way I understand DSB (4-6") is that eventually it will be depleted. At which point you either have to replace it or allow the tank to crash (apparently this is years down the road though).

Given those choices, if I ever do a DSB (I haven't to date), it will be remote (aka refugium or similar). Much easier to replace down the road.

Personally, I advise against a true DSB in a DT.

A quasi DSB (3-4") just seems pointless to me. A shallow bed of say 1-2" is still plenty deep enough for any snails and 99% of fish you might want to keep...

Also, it is clear it is not necessary as plenty of folks go with a naked bottom.

 

I think that DSB crashing is a myth... folks blaming a crash on a DSB instead of some other underlying cause.

There was a REALLY LONG thread about it on RC, with good bits of both science and experience, and I won't get into it here, because I was merely a spectator in the discussion, but I recommend you check it out.

I'm not sure what you mean by deplete; the sand, the bacteria, or the anoxic area?

Sorry to link to another forum, but here is the highly informative thread:
Deep Sand Bed -- Anatomy & Terminology - Reef Central Online Community

 

I wouldn't advise a dsb in your display. If I could do it over again I would have a remote dsb in a 5 gallon bucket. Here's a good article on the pro's and con's. It covers the remote option pretty well.

DSB article - CALFO

 

Actually, it depends on how one defines a crash. To an SPS keeper a crash is when the darn things reverse on you and start spitting phosphorus and Ammonium into the water column. (Remember Ammonium is just as efficient at growing algae as Nitrates are).

Other crashes are made much worse by a DSB. If one loses power, all of those bacteria continue respiration. CO2 goes up and DO (Dissolved Oxygen) goes down quite rapidly. Which kills a fish which causes more Ammonia, which kills another fish which causes more Ammonia and so on. (This is why if one wants to use this for Nitrate reduction, it's best to be remote so it can be removed from the system in a power outage with a simple switch of a ball valve).

People have had crashes when a powerhead suction cup failed and it stirred the sand down to a Hydrogen Sulfide zone which nukes the tank. I had something similar happen but it wasn't a powerhead. David knew the rules....he was NEVER to touch my tanks. One day he decided to "help" me and make the sand look better by stirring all of it with his hands. Well, his "help" killed everything.....all worms, chitons, limpets, copepods, amphipods, snails, etc.

DSB crashes are not a myth. I've been helping people with their aquariums for years and I've helped many a friend remove their DSB after it caused a crash. I always love how people say, "Well, I have had a DSB for 5 years and it's not caused me a problem". To that I say, "Yet".

If you want a DSB, that's fine with me. However, I think one should go into it looking at all pros/cons.

BTW, stickied on the top of this forum is a good thread. Covey put in his DSB. Then he had to remove it some time later. http://www.3reef.com/forums/sand/bb-vs-dsb-34593.html

 

Hey thanks for those experiences! Sorry, I guess I should have said that DSB's crashing on their own is a bit of a myth. But I agree with all the very good points you make.

I'd also agree with going against a DSB in the display now that I know more about them... since mine is 4" or so all the way around, do you think this is enough to be considered a DSB? If it is, how would you recommend going with less of a DSB and more of a SSB if my system is fairly established?

 

I have an ssb. It's 1 1/2" most places with some areas going around the 2" mark. It works for me. There's enough sand to keep everyone happy and I do have a few sand critters.