what is all of this dsb crash talk i read?

[Randy Holmes-Farley]

Explain to me how you can have denitrification and separate all the other things from detritus.

Are you familiar with the Redfield Ratio?


I'm waiting on your explaination.

I don't understand the question. If the sand bed takes out a lot of nitrogen, leaving phosphorus, and I use iron oxide to bind the phosphate, I can keep phosphate and nitrogen low.

[Bomber]

Originally posted by Randy Holmes-Farley
Explain to me how you can have denitrification and separate all the other things from detritus.

Are you familiar with the Redfield Ratio?


I'm waiting on your explaination.

I don't understand the question. If the sand bed takes out a lot of nitrogen, leaving phosphorus, and I use iron oxide to bind the phosphate, I can keep phospahte and nitrogen low.

Yes you can. You can keep it low for the most part. Unless your algae goes sexual, you don't clean it in time, any one of a dozen different things do or don't happen.
The animals you're able to keep will be dictated by that "low" level or their tolerance to a screw up.

What has to be taking place in a closed system for you to have a "low" level?

Your sink is full, it's not performing denitrification properly, you're layers a screwed up and you have a low level of P.

[Randy Holmes-Farley]

Explain to me how you can have denitrification and separate all the other things from detritus.

Are you familiar with the Redfield Ratio?


Macroalgae also do not necesarily follow a Redfield Ratio. The relative amounts of nitrogen and phosphorus in their bulk varies quite a bit. Also, if one is higher than the other, then they can take up relatively more of that one. This provides a buffer against imbalances.

See Table 2 in:


http://www.botany.hawaii.edu/Bot482/...Mar%20Biol.pdf

[Bomber]

Originally posted by Randy Holmes-Farley
I don't understand the question. If the sand bed takes out a lot of nitrogen, leaving phosphorus, and I use iron oxide to bind the phosphate, I can keep phosphate and nitrogen low.

Plus you're completely ignoring everything you taught me about fractions and diffusion.

[Atoller]

Originally posted by Bomber
Yes you can. You can keep it low for the most part. Unless your algae goes sexual, you don't clean it in time, any one of a dozen different things do or don't happen.
The animals you're able to keep will be dictated by that "low" level or their tolerance to a screw up.

Or their ability to use enzymes such as alkaline phosphatase, depending on the richness of the P sink and its proximity to photic conditions. Cyano anyone?

[Bomber]

Originally posted by Randy Holmes-Farley
Macroalgae also do not necesarily follow a Redfield Ratio.

Sand beds do when you throw them off that far.

[Bomber]

Originally posted by Atoller
Or their ability to use enzymes such as alkaline phosphatase, depending on the richness of the P sink and its proximity to photic conditions. Cyano anyone?

Shhhhh, don't confuse him.

[witfull]

simple mans analogy... a sandbed is like a junk closet,,,when you first start putting "stuff" in, no problem, then every once and awhile you have to go in and perform "junk" maintainence, if you keep putting it off and continually put more and more "stuff" into the closet,,,,one day the closet door is going to be opened and a all the accumulated "stuff" is going to fall all over.

some of you may know me others not, but i have had BB tanks, SSB's,and DSB's. personally i prefer BB. one of my biggest problems with DSB's besides the sludge factor is the detrivore kits that one must continually resupply. first im a cheap bugger and paying $100 for bugs in my mind is crazy. second, due to the limitations of an aquarium as opposed to "nature" is that there is only so much O2 that can be sustained in our tanks. if i have all these bugs and (dare i say it?) worms consuming O2 what happens when lights go out and everything in the reef begins to be a consumer of O2? levels of disolved O2 go down...pH falls(% depends on load of tank).

there are good and bad with every set up and design, but when the bad are more than the good, its time to shelve the experiment. i know the mantra "didution is the solution yadda yadda" but how do you dilute a DSB?

last but not least the ever famous saying,,,"but they look so natural!" (shudders,,,i cant even go into this one)....mike, jerel?,,,lol

[Randy Holmes-Farley]

Sand beds do when you throw them off that far.

I don't know what that sentence means, but you apparently ignored the fact that the macroalgae may be able to take up some slack of excess phosphate.

Nevertheless, I quite agree and have said for years that the fact of reducing nitrate and not phosphate does negatively impact the ability to reduce phosphate in biological ways, such as macroalgae.

Luckily, my macroalgae is far more efficient at removing both N and P than is the sand bed under them in my refugium, so that seems to not be an issue, at least in my aquarium.

[Randy Holmes-Farley]

You told me. You're running a algae filter and it's working. You said you have a low level of P in your system and you said algae filters are your preferred way to handle nitrates.


I beg to differ on how that can tell you anything about the nutrient levels in my aquarium based simply on the type, rather than the details of the filtration and inputs.

While I do not cliam that phosphate is at or below natural levels, it certainly theoretically can be using algal filtration. Macroalgae can grow at natural levels of phosphate, and if you have enough of it relative to the inputs, can at least bring down phosphate to that level. Whether it can drop if further, I do not know, because I do not know how much below natural phosphate levels the macroalgae species that I use can still pull phosphorus from solution.

[SPC]

Originally posted by Randy Holmes-Farley
You told me. You're running a algae filter and it's working. You said you have a low level of P in your system and you said algae filters are your preferred way to handle nitrates.


I beg to differ on how that can tell you anything about the nutrient levels in my aquarium based simply on the type, rather than the details of the filtration and inputs.

True story... when I removed my DSB from my refugium, I went from removing a half gallon or so of caulerpa from my refugium every couple of weeks, to removing none at all at about the one month mark. At 2 months I decided to remove what little caulerpa was left. BTW, all tank maintenance, feeding, equipment etc... stayed the same during this period of time.
Steve

[Randy Holmes-Farley]

How long had that sand bed been around?

Was it black at all inside?

[Bomber]

Originally posted by Randy Holmes-Farley
I don't know what that sentence means, but you apparently ignored the fact that the macroalgae may be able to take up some slack of excess phosphate.

And you are totally ignoring the fact that unless you've invented the perfect algae filter and the perfect remote filter at the same time, You have to have a higher level of P in the main system in order to support that algae.

AND that you would not have that P to make that algae filter work in the first place if you didn't have water soluble highly reactive P AND you would not have highly reactive water soluble P floating around in your water unless it has no where else to go.

That everything that could possible sink it, tie it up, use it, store it - did not need it cause it's full already.

The litmius test for Oligotrophic reefs heading south is when they start growing that same algae.

[shred5]

Originally posted by SPC
True story... when I removed my DSB from my refugium, I went from removing a half gallon or so of caulerpa from my refugium every couple of weeks, to removing none at all at about the one month mark. At 2 months I decided to remove what little caulerpa was left. BTW, all tank maintenance, feeding, equipment etc... stayed the same during this period of time.
Steve

Have you measured your phosphate.. Has level changed?
I cant believe I am getting into another one of these things..
What i have said before is yes I believe that phosphate does leech back, But at what rate?
Can it be safely removed?
Thats my question, can we control it?

The dsb provides lots of food and diversity for the tank …
Do you now have to feed more?
Are the benefits of a dsb greater than the down side and are the downside risks manageable?

What are people doing with sps bare bottom tanks to remove phosphates that use a calcium ?

What are people doing to manage nitrates and phosphates in a barebottom?
Don’t say you remove it before it has a chance to break down… Because that is impossible to remove it all and get all before it has a chance to break down.. Sooner or later it will build up?
More water changes?

Dave

[photobarry]

The dsb provides lots of food and diversity for the tank …
Do you now have to feed more?

Most SPS corals farm their own bacteria so don't need additional food. And now there's evidence that at least 1 coral (and most likely many others) contains cyano within its tissue that fixes N2 for the dino's.

What are people doing to manage nitrates and phosphates in a barebottom?
Don’t say you remove it before it has a chance to break down… Because that is impossible to remove it all and get all before it has a chance to break down.. Sooner or later it will build up?
More water changes?


Where is it going to build up if you have enough flow to keep detritus in suspension?

[Bomber]

Originally posted by Randy Holmes-Farley
I beg to differ on how that can tell you anything about the nutrient levels in my aquarium based simply on the type, rather than the details of the filtration and inputs.

Because of the above. Unless you invented the perfect algae filter and the perfect remote filter at the same time.

Maybe you shouldn't have taught me about fractions and diffusion.

[Bomber]

Don’t say you remove it before it has a chance to break down…

Why not? That's exactly what you do.

Ammonium and water soluble P are highly desirable. We just keep plenty of habitat for the things that like it by removing them in their incorporated states. We don't wait on them to break back down again.

[Randy Holmes-Farley]

Where is it going to build up if you have enough flow to keep detritus in suspension?

In the water column itself, if you do not have adequate export. I know that you guys like like to yak about detritus, but don't forget soluble forms of N and P.

[gregt]

Originally posted by shred5
Have you measured your phosphate.. Has level changed?

You can measure only orthophosphates - those dissolved in the water column. Just because you read 0 doesn't mean there are no phosphates in your system.

What i have said before is yes I believe that phosphate does leech back, But at what rate?

Depending on the situation it could be very slow or very quickly. That's my dislike about DSB's. You can't control them.

Can it be safely removed?
Thats my question, can we control it?

See above.

The dsb provides lots of food and diversity for the tank …
Do you now have to feed more?

No, you can feed less. You don't have a giant ecosystem in your sandbed to keep alive.

Are the benefits of a dsb greater than the down side and are the downside risks manageable?

What are the benefits? My BB system is accomplishing everything my DSB did with less effort and concern about the future.

What are people doing with sps bare bottom tanks to remove phosphates that use a calcium ?

I don't undertand this one.

What are people doing to manage nitrates and phosphates in a barebottom?

Heavy skimming and flow which does not allow detritus to be trapped or to settle in the tank.

Don’t say you remove it before it has a chance to break down… Because that is impossible to remove it all and get all before it has a chance to break down.. Sooner or later it will build up?
More water changes?

No, it won't. I'm not adding phosphates 24 hours 7 days a week. I am removing it 27 hours 7 days a week. My flow rate and skimmer size is such that it will be removed long before it breaks down. I do have to be concerned that my pumps keep running, but it's a whole lot easier to maintain a pump, and it's INFINITELY easier to tell when a pump is no longer working.

[Bomber]

Originally posted by Randy Holmes-Farley
In the water column itself, if you do not have adequate export. I know that you guys like like to yak about detritus, but don't forget soluble forms of N and P.

*sigh*

Ammonium and water soluble P are highly desirable. We just keep plenty of habitat for the things that like it by removing them in their incorporated states. We don't wait on them to break back down again.

AND that you would not have that P to make that algae filter work in the first place if you didn't have water soluble highly reactive P AND you would not have highly reactive water soluble P floating around in your water unless it has no where else to go.

[Randy Holmes-Farley]

Or their ability to use enzymes such as alkaline phosphatase, depending on the richness of the P sink and its proximity to photic conditions. Cyano anyone?
--------------------------------------------------------------------------------



Shhhhh, don't confuse him.

I do not know whether the the Caulerpa racemosa and Chaetomorpha species that I use are capable of upregulating alkalinity phosphatase in a way that allows them to take greater advantage of certain organic phosphates (as other certain algae do in low Pi conditions), but I'd be happy if they did so.

[Randy Holmes-Farley]

Ammonium and water soluble P are highly desirable. We just keep plenty to habitat for the things that like it by removing them in their incorporated states. We don't wait on them to break back down again.

You do it with corals and bacteria (I presume that is your claim).

I do it with macroalgae, corals, and bacteria.

What is the fundamental difference?

[MiddletonMark]

Shred -

Actually, I've never heard anyone say or recommend that they don't feed their tank now that they have a DSB ...most recommendations are to feed more, to support all that life.

Personally, I'm highly skeptical about the amount of food produced in the sandbed - but that's my take on it.

Diversity ... great in society - but why do I need it in my reef tank? Do the Acropora color or grow faster in the presence of a certain # of copepods? Does my Monti swirl more when there's more species of worm present? Is my BTA more bubble-tipped if it has a DSB?

To me it's more disparate creatures with differing needs. As it will never be a stable population over the long term, it will need to be replentished regularly ... and is a huge consumer of Oxygen ... that's a fair amount additional bioload just for the sandbed. Add on the critters you're not supposed to have that might eat the critters [most shrimp, crabs, some stars] ... and it becomes less of true diversity and more of a selected diversity.

Personally, I'm boggled at the nitrate boogeyman. Maybe I starve my fish or something, but post-cycle in my 58 I've never read more than low single digits in Nitrate, and under 1 ppm in the last year, with almost all my tests with `clear water' in the Salifert test.

Only had a 5" x 12" DSB in the fuge for about half this time - and for that same period about 1/2" cc/sand substrate ... but since removing it still have undetectable nitrates. Maybe my one clam helps out a bit ... but I'm confused on what the huge nitrate issue is. Yes, if you overfeed, overstock, under-export ... nitrates are a problem.

Thus it boggles me on why people are so freaked out about Nitrates, esp in a SPS tank with high flow and good skimming.

Maybe I've got a blue thumb or something, I guess ... but it seems to me that while I have no doubt that Nitrates are not good in concentration with most of our livestock ... I feel like it's been made into a big, uncontrollable problem that in a well designed/stocked/run system might not be the boogeyman it's made out to be.

Maybe we're scaring newbies with unknown issues with DSB's ... but I feel like we've also scared them to death about nitrates. Personally, we should scare them about overstocking or rushing instead ... as IMO a DSB facilitates overstocking and poor export/import balance.

-- This thread is amazing though, I've been reading along learning for the last few days ... even when I already knew it all first

[photobarry]

Originally posted by Randy Holmes-Farley

In the water column itself, if you do not have adequate export. I know that you guys like like to yak about detritus, but don't forget soluble forms of N and P.

But those are the things that living organisms need. I could see them building up in the water column if you had a completely sterile tank but bacteria and other living things will pull them out of the water column. The bacteria then form the detritus that gets skimmed out. That's why we like yacking about it.

[Mojoreef]

Dave I cant speak for others but I do have a BB with sps. My main concintration is on just removing detritus from the tank. Good flow keeps it suspension and the skimmer removes the vast majority, LR seems to be picking up the balance. With the removal of the detritus/waste I have had no problems with P or N products, no real noticable algae problems either.
The vast majority of P and N are bound up in bacteria as the detritus and waste are thier food source, in removing the waste/detritus you are removing the available P and N along with the critters that have it bound up organically. I havent done a water change in almost 3 and a half years so I cant say that is helping. Kind of a Win win.
On the food source, say for corals. The vast majority of corals eat detritus/waste from fish, which I have plenty of that. Keeping in suspension I am making it available for the corals instead of letting it become food for the sandbed fauna.
Thiier are so many concepts and methods for exportation I ahve never understood way all that stops when it comes to a DSB??? Is aquarium composting the exception to the rule??

Mike