Weekly Discussion - BB vs DSB

[DonJasper]

In a nutshell, the flaw with the BB tanks is that

... you've got to vacuum out the crap all the time. Hey when I was still buying virgin vinyl records - that's those black plastic disks you see in museums now - that's the way I kept a tank for as long as I cared to. Vacuum the (ah hem) detruis out of the sand every couple of weeks.

Now take 1,000 reef keepers of varying ability all poking around inside their tanks with hoses. Well fish are gunna jump, corals get damaged, the wrong stuff sucked up. Some will get tired of the routine and let the crap build up.

So a far more interesting question - to me - which system requires the least amount of operator ability to grow colorful sea creatures in?

 

[Anonymous]

Weekly Discussion - BB vs DSB

There have been discussions about these two methods for the last year or so. What do you think of them, why, and why do you think of the process of discussion?

About the RDO Weekly Discussion:
This discussion is meant to get at your experience and to share information that is in your head, so don't necessarily treat it as information gathering. State your opinion and, if available, use material, anecdotal or otherwise, that will back up your opinion.
Past weekly discussions will be archived in the archives.
If you have topics that you think would be helpful for the RDO community to discuss, please send me a pm or start your own thread! :mrgreen:

Excuse my ignorance but what is BB....is that Bare Bottom?

 

[DonJasper]

Yes, or 'dead sand bottoms'. Some people like the look of sand at the bottom of a tank, but don't want it to do anything biologically meaningful. So you have to vacuum it clean periodically. That way the Ammonia -> Nitrite -> Nitrate cycle never completes. Hence the reduced skimming reported by one poster. So you could view it as a mechanical way of dealing with waste - you physically remove it from the environment.

With DSB's the idea is that you setup up a biological process so that the product of one cycle becomes food for the next. Until you end up with benign things like Nitrogen, Oxygen, and Carbon Dioxide as bubbles. Or some not so nice stuff like Hydrogen Sulfide as stinky (and deadly) bubbles.

Elbow grease or biologics – you make the call!

 

[Mihai]

Oh man, that was an eye opening discussion.

I have exactly 0 experience in this hobby, so I'll not have an
opinion, just a question. I'm interested to find out about this
subject as I'm currently setting up my tank I for now I have a 6" DSB,
but I can get rid of it if needed.

I understand that the DSB can be a sink/sponge for phosphates. Once it
is "full" wouldn't it be from this point of view just like a BB? That
is, once full, it will not take any more phosphates and they'll end up
as algae and perhaps exported? Why is this any worse than a BB?

The algae blooms mentioned several times in this thread seem to happen
only if a significant amount of phosphates will be released suddenly
(in bursts), but I can't figure out why would that happen...

Thanks in advance for enlightening me,
Mihai

 

[Anonymous]

Oh man, that was an eye opening discussion.

I have exactly 0 experience in this hobby, so I'll not have an
opinion, just a question. I'm interested to find out about this
subject as I'm currently setting up my tank I for now I have a 6" DSB,
but I can get rid of it if needed.

I understand that the DSB can be a sink/sponge for phosphates. Once it
is "full" wouldn't it be from this point of view just like a BB? That
is, once full, it will not take any more phosphates and they'll end up
as algae and perhaps exported? Why is this any worse than a BB?

The algae blooms mentioned several times in this thread seem to happen
only if a significant amount of phosphates will be released suddenly
(in bursts), but I can't figure out why would that happen...

Thanks in advance for enlightening me,
Mihai

the theory is that DSBs will absorb phosphates and become saturated with them. then the DSB will release them back into the system in an uncontrollable manner.
BB is supposedly superior for for it's lack of the detritus trap.
i am not sold yet.

 

[Anonymous]

Also, the phosphate released can be deadly to your animals.
What triggers the rerelease is clouded, but could/does have to do with ph changes, temp changes, salinity changes, sand fauna changes or physical changes.
It is unknown if a rerelease is unstoppable.
In a BB you cant have a rerelease.

 

[Mihai]

I see, so it's not a mechanical process (produced by animal or human sifting of the sand)? This is so weird: so many articles documenting the process, but no explanation on what actually triggers the releases: the peer review of that papers is questionable . Just kidding, but it is a major
drawback of those paper.

Thanks,
Mihai

 

[Anonymous]

I can't say for certain if a DSB is destined to inevitably crash a system or not. I've seen a few decade plus old tanks with DSBs as well, and they certainly look fine. These tanks also have a maintenance routine similar to what Len describes for his tank--large biyearly water changes, no human stirring, and a wide array of low impact sand stirrers like cukes, serpent stars, various polychaetes, etc.

If you ask me, part of the purpose of having a fine sandbed is to keep a wider range of animals in your tank. There are some really neat animals (spaghetti worms, conchs, sea cucumbers, pistol shrimp, to name a few) that either need or will do better in a system with a bed of fine deep sand. If you want to grow coralline algae and SPS specimens and nothing else, a DSB probably isn't for you. If you'd like to see another (This is why *I* keep a reef tank) fascinating microhabitat in your living room, maybe it is. Just me 2 cents.

 

[Anonymous]

I see, so it's not a mechanical process (produced by animal or human sifting of the sand)? This is so weird: so many articles documenting the process, but no explanation on what actually triggers the releases: the peer review of that papers is questionable . Just kidding, but it is a major
drawback of those paper.

Thanks,
Mihai

Actually I think those papers do contain the explanation. Ph, temp and salinity changed can all trigger release of phosphates, as can 'mechanical' stirring, as in a storm. What is unclear is how or when phosphate get re released in the aquarium.

 

[John_Brandt]

Is there any research that has determined that phosphate is not liberated or "released" from a captive sandbed on a continual basis from the outset?

 

[Mihai]

I absolutely love biodiversity. So I'll try my luck with a DSB. I hope I'll not hate myself for that later...

Regarding the PH, temp and salinity changes... we
can have those in aquariums as well, don't we? A simple one week vacation + one dead cucumber (or empty top-off, or broken heater, etc.), can change the above parameters, and puff, the phosphate goes berserk. Right?

M.

 

[Anonymous]

Is there any research that has determined that phosphate is not liberated or "released" from a captive sandbed on a continual basis from the outset?

AFAICT, there is no research at all on captive sandbeds.
There certianly is not any about phosphate release in a captive sandbed.

 

[Anonymous]

Regarding the PH, temp and salinity changes... we
can have those in aquariums as well, don't we? A simple one week vacation + one dead cucumber (or empty top-off, or broken heater, etc.), can change the above parameters, and puff, the phosphate goes berserk. Right?

IIRC if those parameters change enough to rerelease phosphste you will have bigger problems than the phosphate. And it is possible that those parameters can change enough in micro 'climates' in your sand.

 

[JerseyReef]

I have to admit something... I've kept myself out of every single thread on this issue, mainly due to a lot of mud slinging on other forums and DSB nay-sayers coming out of the live rock

I think system failures make DSB's easy targets for finger pointing. Why? Poor husbandry skills (or practices) for inexperienced hobbyists for starters. A DSB or any other method takes experience, patience and dedication which the average hobbyists does not have.

Why does every single hobbyist that has a problem with their closed system, point to an easy target. Instead of looking at the real problem? How many people jumped on the plankton bandwagon before understanding if their system could handle the bioload? I'm fairly postive not too many.

Why is credit never given to the hobbyist who has had success with a DSB? Every time someone totes their system, they're called liars or better yet "it's only been up for 3 year's, wait your crash is coming". How about tha fact I had mine up for 5 years with never once a problem with my system. Why? I had the patience to set it up correctly and maintain it when required.

I set my system up as follows:

My tank was setup for 5 years, from 98 to 03 (torn it down due to a house move). It was 5-6" at most places and never once had an algae problem.

I bought four 44lbs buckets of ESV and mixed it in with a bag of slightly larger size Carbsea. Started the cycle with some dead shrimp and waited for three months before adding a critter kit. If memory serves, I bought one from Inland, IPSF and another company that escapes me (somewhere in Tenn?). Fed the DSB for 3 months with nothing but shrimp, fish and pellets. Added some live sand from my fellow reefers in the area and then added my LR, which was fully cured at the time. Waited another two months before any fish, corals and inverts were added. The entire time the tank was skimmed using rev'd up Remora Pro (MAG7). The tank had good flow, I wouldn't call it Tunze sytle flow, but none the less it had flow.

Someone please explain to me why my system thrived? I'll answer any questions you have, about my setup, system, etc...

P.S. - I had a huge bio-load and I fed heavily and I mean heavy