Live rock + DSB - how the heck?

Been running my systems with no mechanical or chemical filtration for
some time, relying soley on live rock and sand for bilogocal filtration.

It works quite well.

My current system keeps nitrogenous waste levels at zero (or close
enough that none of my tests detect them)
ammonia, nitrite, nitrate, all 0.

Prior to this, I had sponge filters and some charcoal in a hang on tank
power filter. Ammonia and nitrites would be 0, but nitrrates would
fluctuate between 5 and 20. (*I still had the DSB and live rock at that
time)

What I don't get is this: It was explained to me that the problem with
intense biological filtration is that it works to well, hence the
nitrate buildup. That makes sense. But if you slow things down, relying
only on live rock and sand for the first two stages, so that the
anaeobic bacteria in the sand and rock can keep up with killing the
nitrates, why do you not see at least a slight rise in ammonia and or
nitrites?

I suppose i should just be happy that it works, but I don't entirely get
why...

If ithere is the proper amount of LR and LS then as the compounds are
created little by little they are inerted just as quick and easy.
Overload the system or cut back on live rock to the point its not more
than or an amount that is necessary to handle the bio load and odds
are you will then see ammonia levels show up.

In al my years of fooling with marine fish, I have yet to ever see
ammonia or nitrite levels show up on a test in an established matured
tank, even if tank did suffer a dead critter unbeknown to me. I tend
to go below suggested BIO load, with livestock stocking rate and also
to go above when it comes to live rock.......but have never been a
fancier of DSB. None of mine are over 1.5" with most at 3/4 to 1"
or so at most. I do go very heavy on liverock however.......

On Mon, 29 Jan 2007 13:52:43 -0500, Add Homonym
wrote:

Been running my systems with no mechanical or chemical filtration for
some time, relying soley on live rock and sand for bilogocal filtration.

It works quite well.

My current system keeps nitrogenous waste levels at zero (or close
enough that none of my tests detect them)
ammonia, nitrite, nitrate, all 0.

Prior to this, I had sponge filters and some charcoal in a hang on tank
power filter. Ammonia and nitrites would be 0, but nitrrates would
fluctuate between 5 and 20. (*I still had the DSB and live rock at that
time)

What I don't get is this: It was explained to me that the problem with
intense biological filtration is that it works to well, hence the
nitrate buildup. That makes sense. But if you slow things down, relying
only on live rock and sand for the first two stages, so that the
anaeobic bacteria in the sand and rock can keep up with killing the
nitrates, why do you not see at least a slight rise in ammonia and or
nitrites?

I suppose i should just be happy that it works, but I don't entirely get
why...



-------
I forgot more about ponds and koi than I'll ever know!

Add Homonym wrote:
I suppose i should just be happy that it works, but I don't entirely get
why...

Both live rock and DSB are anaerobic beneath the layer exposed to
oxygenated water, so the bacteria need to find another oxygen source.
The NO3 (nitrate) makes a nice source for this, and it release nitrogen
gas in it's wake.

--Kurt

"Add Homonym" wrote in message ...
What I don't get is this: It was explained to me that the problem with
intense biological filtration is that it works to well, hence the
nitrate buildup. That makes sense. But if you slow things down, relying
only on live rock and sand for the first two stages, so that the
anaeobic bacteria in the sand and rock can keep up with killing the
nitrates, why do you not see at least a slight rise in ammonia and or
nitrites?

Let me try... When you add a canister filter, sponge or any other
mechanical filtration to your tank you are catching organic debris
in the mechanical media and it accumulates there. Plankton,
pieces of live algae, amphipods... they get trapped in the sponge
and they die there. If you keep your mechanical filter clean, let's
say clean your sponges every day - than you should not see the
problem... But who could be disciplined to do it ? :-)
So the fact is that this sponge or canister is left for weeks or
months with this organic matter trapped there, rotting and turning
into nitrates very efficiently. In most cases it is EXTRA material
which would be normally living tissue in the tank (plankton) or
got eaten by some animal (amphipod or worm in your sand).

Now - anaerobic conversion has quite small capacity - it cannot
deal efficiently with increased load. Aerobic conversion, turning
ammonia into nitrates is quite opposite: as long as you provide
nice water flow and water contains oxygen than with more food
you will quickly have more nitrating bacteria, quickly overwhelming
anaerobic counterparts and destroying previous ballance with them.

So adding mechanical filtration and not cleaning it at least every
day not only improves aerobic conversion, but also ADDS amount
of the organic gunk bacteria is feeding on by converting living
tisue or detritus which could be eaten by worms in your tank with
food for your aerobic bacteria.

This is how I understand the process...
But I am not a marine ecologist so I might be very wrong here :-)

Pszemol wrote:
"Add Homonym" wrote in message
...

What I don't get is this: It was explained to me that the problem with
intense biological filtration is that it works to well, hence the
nitrate buildup. That makes sense. But if you slow things down,
relying only on live rock and sand for the first two stages, so that
the anaeobic bacteria in the sand and rock can keep up with killing
the nitrates, why do you not see at least a slight rise in ammonia and
or nitrites?
snip
So adding mechanical filtration and not cleaning it at least every
day not only improves aerobic conversion, but also ADDS amount
of the organic gunk bacteria is feeding on by converting living
tisue or detritus which could be eaten by worms in your tank with
food for your aerobic bacteria.


Ding Ding Ding - I think we have a winner here. THIS makes a lot of
sense. I had foam prefilters over my powerheards, over my skimmer
intake, and a foam block in my hang on power filter. I think what was
going on is exactly what you describe above.

"Add Homonym" wrote in message ...
THIS makes a lot of sense.

The real question is - is it true explanation or not ? :-)

Also, the idea of no mechanical filtration, which I was advocating here
for long time after reading convincing arguments online does not work
all the time. In particular, it did not work for me. I had no mechanical
filtration in my 58 gallon tank with two big fish and two smaller ones.
The buildup of detritus was overwhelming... The fauna in the sand bed
(DSB) could not keep up with processing waste so I had constant problems
with hair algae. After the sand bed cycled and nitrates went down to zero
(not measurable) I had red/maronn cyanobacteria blooms on almost
every surface of the tank.

I got algae under control after using phosphate removals and cyano
was partially gone, but amount of detritus from dying algae and fish
waste was still making the water dirty...
The real break trough was when I started using filter sock over my
drain pipe in the sump and blowing rocks in the tank with a turkey
baster - the amount of brown/beige stuff (detritus) collected every day
in my filter sock is amazing. The water is much clearer now and I do
not see so much algae growth on the rocks...
Occasionally I take a toothbrush and clean the rock from dead algae
and flying detritus dust in the water is filtered by the sock in the sump.

Very positive side effect of the filter sock in the sump is that it greatly
limit the amount of air bubbles in the sump finding their way to the
return pump and back to the tank. I had the problem with air bubbles
because my ghetto sump is simple 10 gallon tank with no dividers...
Now with a filter sock I have virtually no air bubbles in the tank.
Water is not turbid anymore and the tank itself looks much better...

So I guess the advice of not having mechanical filtration is good only for
reef tanks which have mostly corals and limited number or no fish at all...
With a lot of fish you probably cannot avoid mechanical filtration, but
keep them on very strict regime of cleaning every day to avoid turning
them into the nitrates factory. I wash my filter sock every day under
running water (no detergent, of course) and the water is literally brown...

Pszemol wrote:

So I guess the advice of not having mechanical filtration is good only for
reef tanks which have mostly corals and limited number or no fish at all...
With a lot of fish you probably cannot avoid mechanical filtration, but
keep them on very strict regime of cleaning every day to avoid turning
them into the nitrates factory.

Thanks. I happen to have a Hot Magnum filter in the closet. It's designed to
hang on the back of a tank. I think what I will do is hook that up and run it
overnight every once in a while. I'll use a turkey baster to kick some of the
detritus into circulation. That should get some of the stuff out of the tank
while avoiding the problem of having it decay in the filter medium.

George Patterson
No one ever says "It's only a game." when his team is winning.

A larger sump with more live rock rubble will take
care of that.

Wayne Sallee
Wayne's Pets


Pszemol wrote on 1/30/2007 11:52 AM:
"Add Homonym" wrote in message
...
THIS makes a lot of sense.

The real question is - is it true explanation or not ? :-)

Also, the idea of no mechanical filtration, which I was advocating here
for long time after reading convincing arguments online does not work
all the time. In particular, it did not work for me. I had no mechanical
filtration in my 58 gallon tank with two big fish and two smaller ones.
The buildup of detritus was overwhelming... The fauna in the sand bed
(DSB) could not keep up with processing waste so I had constant problems
with hair algae. After the sand bed cycled and nitrates went down to zero
(not measurable) I had red/maronn cyanobacteria blooms on almost
every surface of the tank.
I got algae under control after using phosphate removals and cyano
was partially gone, but amount of detritus from dying algae and fish
waste was still making the water dirty...
The real break trough was when I started using filter sock over my
drain pipe in the sump and blowing rocks in the tank with a turkey
baster - the amount of brown/beige stuff (detritus) collected every day
in my filter sock is amazing. The water is much clearer now and I do
not see so much algae growth on the rocks...
Occasionally I take a toothbrush and clean the rock from dead algae
and flying detritus dust in the water is filtered by the sock in the sump.

Very positive side effect of the filter sock in the sump is that it greatly
limit the amount of air bubbles in the sump finding their way to the
return pump and back to the tank. I had the problem with air bubbles
because my ghetto sump is simple 10 gallon tank with no dividers...
Now with a filter sock I have virtually no air bubbles in the tank.
Water is not turbid anymore and the tank itself looks much better...

So I guess the advice of not having mechanical filtration is good only for
reef tanks which have mostly corals and limited number or no fish at all...
With a lot of fish you probably cannot avoid mechanical filtration, but
keep them on very strict regime of cleaning every day to avoid turning
them into the nitrates factory. I wash my filter sock every day under
running water (no detergent, of course) and the water is literally brown...

Ammonia is still being produced. The fish produce it
and so does food that rots. With more live rock, and
more live sand, you have more critters there to eat
uneaten food. If the food is caught in a filter it
tends to be less available for critters to eat it,
thus bacteria convert it into ammonia. Amphipods
often live well in such a filter, but the uneaten
food is put to better use if it is spread out in the
live rock, and live sand. Spaghetti worms are great
they take the food down into the sand, and this
helps feed the low oxygen bacteria, thus reducing
the nitrites and nitrates. Nitrification converts
nitrites into nitrates, but denitrification converts
nitrites into nitrogen, and nitrates into nitrites.
It takes longer for them to convert nitrates into
nitrogen, than it does to convert nitrites into
nitrogen, thus if the aerobic bacteria keep quickly
converting nitrites into nitrates, it makes it
harder for the low oxygen bacteria to keep up with
denitrification.

Wayne Sallee
Wayne's Pets


Add Homonym wrote on 1/29/2007 1:52 PM:
Been running my systems with no mechanical or chemical filtration for
some time, relying soley on live rock and sand for bilogocal filtration.

It works quite well.

My current system keeps nitrogenous waste levels at zero (or close
enough that none of my tests detect them)
ammonia, nitrite, nitrate, all 0.

Prior to this, I had sponge filters and some charcoal in a hang on tank
power filter. Ammonia and nitrites would be 0, but nitrrates would
fluctuate between 5 and 20. (*I still had the DSB and live rock at that
time)

What I don't get is this: It was explained to me that the problem with
intense biological filtration is that it works to well, hence the
nitrate buildup. That makes sense. But if you slow things down, relying
only on live rock and sand for the first two stages, so that the
anaeobic bacteria in the sand and rock can keep up with killing the
nitrates, why do you not see at least a slight rise in ammonia and or
nitrites?

I suppose i should just be happy that it works, but I don't entirely get
why...