Deep Sand Bed -- Anatomy & Terminology

[Whys]

I'll be honest Paul, I too have my doubts regarding the efficacy of relying upon subsurface sand critters. In truth, I'm a bit surprised my DSB hasn't gone bad, for a variety of reasons. One, I have an extreamly low bioload and that seems to put a significant limit on my subsurface sand critter population, as there just isn't much to eat. Not to mention my repeated and agressive FWE dosing that, from what I can tell, has detrimentally impacted thier numbers. Second, except in a few spotty mid-layer locations, my sandbed doesn't have the characteristic trapped nitrogen bubbles one expects to see. Thus the lower layer of my sandbed doesn't churn in the slightest and visual indication would suggest it is not a functional DSB. None the less, nitrate levels have never been detectable despite infrequent waterchanges of about 30% every 2 months. There is no rotten-egg smell, no dark discolorations under the surface along the glass, and all my tank inhabitants remain healthy.

I can only conclude that my DSB is minimally functional because of my minimal bioload and that the minimal bioload keeps the bad bacteria below starved of nutrients. But I suspect the real key to its current success is due to two factors. One, I have *ample* water current at sand level due to pumping my return in at sand level. Two, I have a mixed grain size substrate that allows flow to more easily penetrate to the deepest layer.

Only time and increased bioload will tell for sure. I think I've finally solved the flatworm problem and will be increasing the bioload shortly.

 

[jenglish]

FWIW, I don't think a population of bristleworms is going to work itself out of existence in a tank, they seem to multiply pretty easily. I never run out and I deep clean my DSB and have seen a few bristleworms go out in the waterchange

 

[Paul B]

Intersting. Whys, and Jeremy, how long are your DSBs running?

 

[Whys]

Tho I have little doubt they can easily replace themselves, I've never seen a bristleworm under the sand, only spaghetti worms and something thread thin and translucent brown. The spaghetti worms seems to populate themselves pretty well, whereas I've seen fewer and fewer of the thread-thin kind. It's possible they've simply moved away from the glass, but I can't really say, since I don't deep clean my sandbed. In fact, I've never touched it.

What I have noticed is yellow and pink patches under the surface along the glass. I assume its bacteria, but don't know if it's good or bad.

 

[Whys]

Paul, just over a year now.

 

[jenglish]

hmmm, this one is about 18 months. I recognize the ability of arag to bind PO4 limits the lifespan of a DSB (unless you used silcate based sand) but I believe that frequent deep cleanings help remove the detritus before it gets to be bound. I know this is different than the traditional Dr. Ron Shimek methods but that is a whole other subject

 

[Aquarist007]

my one deep sand bed has been running for three years, the other two years. With my huge bioload they must be doing the job because I have undetectable nitrates and little algae to none in the display tank.

 

[tmz]

Without nutrient movement into the lower layers the bed can still function quite effectively in the top inch where there should be a good deal of denitrification occuring. The deeper sand may just be sterile. With the alternatives availalbe today for nutrient management and the cited studies showing depth in a bed doesn't matter much as far a denitricfication ,unless the nutreints are moved down, I would not recommend a dsb except for those who like it aestheticly or who wish to keep certain fish and invertebrates that require it.having said that I still have a tank with a 7yr old bed,

 

[Whys]

...I still have a tank with a 7yr old bed,

And congratulations on your success, Tom.

Personally, I find it a bit amusing that critiques first complain that a DSB doesn't last more than a year. Then someone like you comes along and they retort with, "well it won't last more than 10." Even if that's true, I have to ask, what does?! Most cars don't last more than 10 years, but that doesn't stop people from buying them. A lot of marriages don't last more than 10 years, but people keep getting married. So just how long does a DSB have to last before the critiques stop criticizing? How many years do most hobbyists stay in the hobby or maintain the same tank or stay in one place? From what I see, moving from house to house is the only insurmountable issue. As I myself will move within the next 5 years, no matter how well my DSB succeeds, I won't be able to say it lasted more than a decade.

First person to find a way to move a DSB, wins.

 

[Paul B]

So just how long does a DSB have to last before the critiques stop criticizing?

57 years and 3 months :beer:

A lot of marriages don't last more than 10 years

Going on 37 :worried:

How many years do most hobbyists stay in the hobby or maintain the same tank or stay in one place?

One :hmm5:

First person to find a way to move a DSB, wins.

Put it in a mobile home

Whys, all good points. I think a DSB works fine for a few years and it's true that most people don't stay put very long. I did move my tank after it was set up for 5 years but my system is easily movable.
I may move again but it probably will not be for a few more years. If that time comes I will just buy a home, put a larger tank in it and transfer everything into it. My old tank will stay here so I hope the people have fish or turtles, ferrets, chinchillas, or rats. :hmm3:

I think DSBs start to decline as soon as they are installed. Of course I am not the God of DSBs so that is only a guess. I came up with that guess from the fact that I can only find one DSB over ten years old out of the thousands that were installed. It may also be true that no other systems last either.
I also think that if your nitrates are rising, no matter what system you have, there is something wrong. Nitrates should never rise, that is we have DSBs, live rock, and all the other "innovations" and technology to reduce nitrates.
I am always amazed at the amount of water people have to change due to nitraes, not just with DSBs but with all systems. I don't think they are paying their bacteria enough :sad2:
To me, and of course only me, if you need to change water to reduce nitrates, your system is not functioning properly and a bare bottom would work just as well.
As my wife tells me all the time, I can be wrong and I am wrong many times. :lol:
But it is just my opinion.

 

[Whys]

Put it in a mobile home

:celeb2::celeb1::celeb3::beer::celeb1:

 

[tmz]

Paul, Congratualtions on 37 years of marriage. Didn't know you were a newlywed. We just passed 41 years.

 

[Paul B]

We just passed 41 years.

Wow, your really a Gezzer :lmao:

 

[jenglish]

57 years and 3 months :beer:

so in 2065? :lol:

 

[Paul B]

so in 2065?

Yes, and I will be dead so you can't say to me Nay nay nay, I told you so :bum:

 

[Aquarist007]

I am more interested in coming up with a statement or two that doesn't become the straight man line for PaulB. I think that task might in deed outlast my current deep sand beds

 

[Whys]

"My DSB is functional, so why are my nitrates so high?"

PaulB ------>

 

[Paul B]

I love it

 

[elegance coral]

When dos sand become old???

Sand is most likely very old by the time we get it. It's not the age of the tiny particles of calcium carbonate that cause us problems. It's the accumulation of rotting organic matter in the sand that leads to problems. So... we have two choices. We can allow rotting organic matter and a gazillion critters that are responsible for its decomposition, to build up in the sand, resulting in a slow decline in the health of the system and the eventual need to start over, or we can simply keep the sand clean to start with and not worry about this problem.

 

[tmz]

It may not be just the decaying matter that fouls it. Some argue, overtime bacterial mulm covers the surfaces and fills the pores along with otehr organic matter which may decrease the surface area available ongoing bacterial colonization. Many replace portions of their sand bed every year or so.