Dsb's work, what makes them work best?

[SDguy]

<a href=showthread.php?s=&postid=6468735#post6468735 target=_blank>Originally posted</a> by aubee91
Is it possible that there are a couple of major mechanisms by which DSB's can work? It appears to me that DSB's as Dr. Ron wants them run are highly dependent on the infauna to work. I would assume that in this case (almost) all nitrates and phosphates are actually bound up in the bodies of the organisms living in the DSB themselves. I.e. worms eat snail poop and snails eat worm poop and smaller snails and worms eat their poop, etc. ad infinitum with the bacteria taking care of what little is left after all the critters get their share. In this case, not much denitrification would actually be occurring but rather nitrates (and phosphates) would be taken care of by the critters eating the nutrients.

In the case of a DSB that doesn't have a lot of infauna or critters, either because they weren't ever added or because they have died, denitrification by anaerobic bacteria is the main (or only) process occurring in the bed. And in this case the bed could or would work like Bomber and some others have proposed with the bed possibly eventually filing up and burping phosphate that has accumulated in the bed as a byproduct of bacterial denitrification.

Might this explain why some work and some don't and why some go for a long time and quit working while others quit working very soon? Feel free to dismiss this completely as I don't fully understand all the concepts and processes involved in this stuff. Which is why I'm reading this thread.

OK, so here's where it starts to get murky for me. We're talking phosphates...organic or inorganic? Then, there's the worry they are binding to the actual sand? Or are they still fixed to the detritus, which is in turn burried in the sand? Then another idea that they are in the living fauna found in the DSB? Are all of these true? Maybe this is the carrot that can lure Randy out of the chemistry forum to maybe shed a little light for me

 

[Acipenser]

Flow?

Flow?

I have some questions for Joe and the changes between his systems.

It looks from the before and after pictures that you added a lot of snails to your new BB tank. Is that true? I could not see really well in the first DSB tank picture. This in itself may have helped the algae problem.

Secondly, flow can not be overlooked in this situation. How much of an increase in gpm do you think you added to your new BB tank? SPS growth can be directly linked to flow. I had a frag in a DSB for about a year. I experienced a good deal of encrustation (about 2" all around the frag) but got no verticle or tip growth. I added another pump and the frag took off. No other changes but flow. I think your increased SPS growth might be primarily due to increased flow.

Also increased flow can increase coraline algae growth (which inhibits nuisance algae growth). Ever look at a tank that has a powerhead facing directly into the glass. It is usually a spot of significant coraline growth.

KBMDALE - This might also be the reasoning for the success in those DSB tanks that you mention have unlevel sand beds. this might be caused by the high flow rates in these tanks.

I think flow is often overlooked as one major factors in tank success.

Just my $0.02.

 

[joefish]

Re: Flow?

Re: Flow?

<a href=showthread.php?s=&postid=6469125#post6469125 target=_blank>Originally posted</a> by Acipenser
I have some questions for Joe and the changes between his systems.

It looks from the before and after pictures that you added a lot of snails to your new BB tank. Is that true? I could not see really well in the first DSB tank picture. This in itself may have helped the algae problem.
I was always adding snails. they kept dying off .The BB pics show them more and I had added some again too.

Secondly, flow can not be overlooked in this situation. How much of an increase in gpm do you think you added to your new BB tank? SPS growth can be directly linked to flow. I had a frag in a DSB for about a year. I experienced a good deal of encrustation (about 2" all around the frag) but got no verticle or tip growth. I added another pump and the frag took off. No other changes but flow. I think your increased SPS growth might be primarily due to increased flow.
Yes flow is a major issue people over look. I don't claim the change to BB was the whole reason for growth , But with less PO4 in the system I'm positive it was a contributer

Also increased flow can increase coraline algae growth (which inhibits nuisance algae growth). Ever look at a tank that has a powerhead facing directly into the glass. It is usually a spot of significant coraline growth.

KBMDALE - This might also be the reasoning for the success in those DSB tanks that you mention have unlevel sand beds. this might be caused by the high flow rates in these tanks.

I agree here , I think that is something overlooked .A good cause and effect.
I think flow is often overlooked as one major factors in tank success.

Just my $0.02.

 

[aubee91]

<a href=showthread.php?s=&postid=6468919#post6468919 target=_blank>Originally posted</a> by SDguy
OK, so here's where it starts to get murky for me. We're talking phosphates...organic or inorganic?

I'm not sure, but I would assume organic in this case since they would be entering the tank in/as food, but I don't know for sure.

Then, there's the worry they are binding to the actual sand? Or are they still fixed to the detritus, which is in turn burried in the sand? Then another idea that they are in the living fauna found in the DSB? Are all of these true? Maybe this is the carrot that can lure Randy out of the chemistry forum to maybe shed a little light for me

I have no idea if they are true. And a little light would be great.

 

[barryhc]

<a href=showthread.php?s=&postid=6468527#post6468527 target=_blank>Originally posted</a> by SDguy
Right, I understand all that. I was more getting at the idea that it will be nice, though difficult, to know why different DSB leech at different times. For example, is it even possible for accumulation to have occurred to such an extent in these situations where the algal bloom is in the first two years? Does this come back to properly curing live rock, and the DSB just ends up being the improperly cured live rock's scape goat??

I really don't think so, and here is where I have some "short-term" experience.

I had about 10 lbs. of base rock, and about 10 lbs. of live rock at the 2 mos. stage of my "little hex" aquarium. Cycling was over for the initial stage, and my nitrates were at about 100 ppm. I had bought some garf stuff, and it basicly just "killed the tank". Bad shipping maybe, I don't know.

I recieved my second batch of live rock ( about 25 lbs. ) at this point and proceeded to "cure it". I got the 16 gal. walmart tub, and put in the power head, the heater, and stuck 40 watts of PC lighting over the top of it 24/7 for 10 days.

Yeah I know, but I figured that if the stuff is going to grow, then just let it, and suck up the nutrients like crazy in the mean time. I can't say if I want to reccomend this, but this is what I did.

Now by a particularly strange coincidence, I had just recieved a shipment of "clean-up crew" from "Fosters and Smith", and for some reason they overshipped by about triple, so I ended up with about 40 snails and 40 crabs in this little tank, and having to figure out how to keep them from starving.

Then with the hair algae at about 1 1/2 to 2" long, I noticed that all those cool looking sponges were getting "covered-up", and not really knowing any better, I figured I had to "save them" somehow, so I decided to just give the food to the "detrivores".

I knew that this a bit out of the ordinary, with several fish and other animals in the tank , but hey, it's my little 27 gal. experiment, so why not just see what happens.

Knowing that the long hair algae was a huge bio-load, I took the smallest algae laden rock, and put it in the display tank to see what happened.

Lo and behold, 2 days later that rock did not have any algae on it. My ammonia was under 1ppm, and the nitrite was at zero, with nitrates at 120 ppm, and the fish and invertibrates didn't seem to mind at all, so in went another rock.

I can't really make the story shorter at this point, but in the interest of "brevity" I will say that 10 days later, 25 lbs. of new heavily algae laden rock was in the tank, and it was "cured". . . . . err, it didn't have any algae on it anymore.

I think the Nitrate got to about 140 ppm, and I did not have a Phosphate kit at that time, I'm sure it was exceedingly high.

So then I ran the tank for a while, and then converted the walmart tub to a make-shift refugium. Just an inch of old gravel, and a dead rock. The "dilution-solution".

I got some xenia after I got the Nitrate under 20 ppm, and added a couple more fish.

This is about the 5 mo. mark. Now here is the interesting thing , I ended up at 0 Nitrates at about the 8 month mark, I rarely change any water, and at the 10 mo. mark, Phosphate made it below .2 ppm.

At the 11 mo. mark, which is now, Phosphate is down to .05 to .1ppm, and I have quite a variety of softies, lps ,critters and fish. The several SPS frags, are not doing that well, as much from not enough light as the High Phosphate.

Now, I have a cucumber, 2 brittle stars, 2 shrimp, a moray eel, 20 crabs, 20 snails, 5 fish, zoos, open brain, torch coral, yada, and blah.

I also have a magnificent sea clone skimmer that I have to hold ever so dear to my heart. No other filtation.

I do not stir, I do not vacuum, or siphon, or else wise do any maintanence inside of the tank. Doh!, EDIT: I clean two panes of the glass, once a week, there isn't much there, or on the other four that I can't clean.

I do not have algae in the tank that you can see. I have only had a brief spell with cyano about 3 mos. ago in the refugium only, right after I fired up the refugium.

All the animals are happy, and I feed sparingly? about 1/2 teaspoon every day, mostly frozen and phytoplankton.

The substrate is as pristeen as the day I put it in, and grows a few pods, and feather dusters.

Do I have a Phosphate problem? Well at .1 ppm, maybe, but it is still on it's way down. So, if I have a problem in the substrate, from curing the rock, when am I going to see it?

I am being faciceous here, I don't have a phosphate build-up in the sand bed.

Could I end up with one, sure I could, but I won't let it happen.

I suppose if you just throw the live rock in there on top of the sand, and let it shed in an otherwise empty tank, it would be worse, but the bio-load and feeding are more important in the long term.

Geeze, shorten them up a bit heh? > barryhc

 

[Sindjin]

Barryhc,

Your experiment is interesting. Let me summarize my recent experience with my new 120, BB....just for kicks and giggles.
On 10/27/05, I put 100lbs of Fresh, UNCURED Fiji LR in my tank along with about 50lbs of base. Every few days I pulled out the rock, dunked/swished the rock in a seperate container of saltwater and changes about 25% of the tank water....while siphoning detritus off the bottom. I did this for 2 weeks. On 11/08/05 my Nitrates were at 40 ppm ...the highest they reached...and PO4 was at .4ppm. By 11/19/05, My Nitrates were at zero and that is where they stayed. My PO4 remianed at .4 for another month until they dropped where thay hover at about .04-.06ppm.

IMO, it was a pretty quick cycle considering I used Uncured Rock!

Could this because I did it in a BB? Meaning I was able to siphon out all the waiste that was accumulating....where as in a DSB it would have all sank into the bed....hopefully no one would cycle a new DSB with UNCURED Live rock but like I said... 3 sites/articles practically told me to do so.

If I were to set up a new tank with a DSB, I would Cook my rock seperately for 3 to 4 months. Then add the cooked rock on top of a new sand bed and start really slow.

 

[SDguy]

<a href=showthread.php?s=&postid=6469343#post6469343 target=_blank>Originally posted</a> by aubee91
I have no idea if they are true. And a little light would be great.

Guess I should have checked the Chem forum first....here's a great read...

http://www.advancedaquarist.com/issues/sept2002/chem.htm

 

[inwall75]

This is a thread to read for anyone wanting to set up a DSB IMO.

I run DSB's and BB systems. One of my tanks could be considered to be a SSB system by some and a DSB by others...it all depends on our "definitions". For purposes of my post and not anyone elses, I will define 4" or greater to be DSB.

I've seen people get into arguments because their definitions of things are different so I thought that the best way to proceed would be to agree on what different things mean.

For some other definitions, let's hit the types of Phosphorus (P)

DIP--Dissolved Inorganic Phosphates
DOP--Dissolved Organic Phosphates
PIP--Particulate Inorganic Phosphates
POP--Particulate Organic Phosphates

This is a HIGHLY SIMPLIFIED EXPLANATION but this is MY definition unless someone has a better one (I don't want to get too technical so newer people don't freak out). Here's my thought.

Organic P--Is bound inside a critter, bacterium, or algae. Not testable by most hobbiest test kits.
Inorganic P--Is not bound inside a critter, bacterium, or algae but may be adsorbed to a Major component of NSW (I.e. Calcium-phosphate, Magnesium-phosphate, etc.) or unbound as PO4. Most of this is also not testable by hobbiest test kits unless it is unbound PO4.

Definitions from the thread previously discussed:

Crash = sudden deaths that occur fast .

Failed= not working right.

IMO, if this thread is going to be successful, everyone has to be on the same page so lets work out common definitions ahead of time.

 

[Weatherman]

<a href=showthread.php?s=&postid=6468580#post6468580 target=_blank>Originally posted</a> by Sindjin
All Rock Cooking is ....is Well Cured Live Rock that Cured in total darkness to kill off algaes.

Having once worked at the National Organization for the Advancement of Acronyms (NOAA), I think we need to find a catchy new acronym for rock cooking.

WCLRTCTDKOA is just too complicated.

 

[SDguy]

<a href=showthread.php?s=&postid=6469753#post6469753 target=_blank>Originally posted</a> by Sindjin
By 11/19/05, My Nitrates were at zero and that is where they stayed. My PO4 remianed at .4 for another month until they dropped where thay hover at about .04-.06ppm.

IMO, it was a pretty quick cycle considering I used Uncured Rock!

I have a question. How did you get your phosphates down in this time period. Since these are orthophosphates you are testing for, they are not skimmable, so siphoning detritus would not work. You either exported them, or they bound to something (ie LR). Am I correct in this thinking?

 

[Sindjin]

I have a question. How did you get your phosphates down in this time period. Since these are orthophosphates you are testing for, they are not skimmable, so siphoning detritus would not work. You either exported them, or they bound to something (ie LR). Am I correct in this thinking?

My best guess would be husbandry. I swished and dunked the LR a lot and continued to blow it off/out with a Turkey Baster. Then I siphoned a lot of detritus off the starboard bottom.

 

[gman0526]

Awesome thread guys keep it going!!!

 

[Sindjin]

OOoo another thing... It was easy for me to blow out the rocks and then siphon the crap out of the tank...but if I had a DSB... I would have done the same process but in a seperate container, in total darkness AND a lot longer...

Im 3 months in and my rock is still shedding. I am a firm believer in cooking. I wish I did it! Then my tank would be pristine.

 

[Sindjin]

SDguy,

That was a great link/article about Phosphate in our tanks! Interesting that pH, Calcium and Alk have such a role.

 

[onthefly]

Since I've used both BB and DSB systems I'll chime in on a couple of observations.

1) Over the last few years, it seems alot of DSB's have been composed of uniform "oolic/southdown" types of beds (probably a cost issue since SD is so cheap!). It's my understanding that most of the DSB "experts" recommend a mixture of several types/sizes of sand. Could these uniform sized beds be "hastening" DSB failures?

2) As for stirring/vacuuming DSBs...and that being a "recipe for disaster". Steve Weast regularly siphons his sandbed (albeit the upper layers), removing sand in the process, and replacing it with fresh sand. So I see a couple things here that apply to this discussion: 1) by slowly using a remove/replace method.....he's avoiding any PO4 sink issues (if in fact that's the case), and 2) It would appear that vaccuuming a DSB is "not" a recipe for disaster.

 

[Sindjin]

I agree... If you begin your tank with light vaccuming your good... but if you decide to vacuum and stir up a 5 year old sandbed...watchout and be careful....you wouldnt want to release any nasty pockets.

I have not setup a DSB reef. BUT I spent the last 10+ years running freshwater Live Plant tanks. ...complete with a deep bed and DIY CO2 generators (yeast and sugar). Anyway... my substrate consisted of a mud layer, sand layer then a fine gravel layer on top. I would periodically siphon out the top gravel layers but would not disturb the other layers. Mostly due to the plant roots BUT also to not release nutrients. Hmmmmm not that DSB's of fine sand and mud are nutrient sinks.

But in a DSB... if you maintained a decent critter count wouldn't they theoretically sift thru the sand? Besides... I do remember reading where a sand bed would be better left undisturbed as to not grind up your critter population.

 

[Weatherman]

<a href=showthread.php?s=&postid=6470822#post6470822 target=_blank>Originally posted</a> by onthefly
2) As for stirring/vacuuming DSBs...and that being a "recipe for disaster". Steve Weast regularly siphons his sandbed (albeit the upper layers), removing sand in the process, and replacing it with fresh sand. So I see a couple things here that apply to this discussion: 1) by slowly using a remove/replace method.....he's avoiding any PO4 sink issues (if in fact that's the case), and 2) It would appear that vaccuuming a DSB is "not" a recipe for disaster.

It appears likely that the purpose of the sand in Steve Weast's tank is for appearance only. There was no intent to set up a sand bed as a denitrifying filter.

If you want to take that route, you need to be willing to keep the sand bed dynamic (always stirred up, continuously removed and replaced).

 

[SDguy]

<a href=showthread.php?s=&postid=6470498#post6470498 target=_blank>Originally posted</a> by Sindjin
My best guess would be husbandry. I swished and dunked the LR a lot and continued to blow it off/out with a Turkey Baster. Then I siphoned a lot of detritus off the starboard bottom.

Hmmm, I also wonder how much impact this rock shedding has on the DSB as compared to, for example, all the food one would be adding to a tank with many fish...on a continual basis. I'm just not sure that, post standard curing, any more detritus will be worse than fish food (eventually poop) entering the system. Both should be handled with a correctly set up tank (skimmer, flow, etc.) But this is for the a cooking thread

As for some comments about stirring your sand...I agree that it depends on why you're setting it up. To keep fauna, a denitrification system, etc manual stirring is bad. Use snails at most. If the sand is purely for aesthetics, then, yes, keep it really stirred up and blowing in the flow In fact, this wouldn't even be a DSB anymore anyways. It shouldn't be as deep either.

 

[bertoni]

<a href=showthread.php?s=&postid=6471751#post6471751 target=_blank>Originally posted</a> by SDguy
Hmmm, I also wonder how much impact this rock shedding has on the DSB as compared to, for example, all the food one would be adding to a tank with many fish...on a continual basis.

I wouldn't "cook" (dark-cure) rock for a DSB. I'd just put the rock into the tank, and try to keep the animals, etc, alive. In a DSB, the focus is on using animals to process waste, etc. Perhaps with some care, the animals could be saved and the rock wouldn't shed as much. Otherwise, I'd just wait.

The whole issue of dark-curing seems irrelevant to me with respect to making a DSB work, anyway, so I consider far the whole issue off-topic.

One of the hardest parts of setting up a DSB is getting the right sand mix. I still don't have a handle on a good supply. None of the Carib Sea products are fine enough. Has anyone looked at the "flour" product to see how it stacks up?

 

[Sindjin]

The whole issue of dark-curing seems irrelevant to me with respect to making a DSB work, anyway, so I consider far the whole issue off-topic.

Thats just it... to me COOKING (dark curing) is even more essential in a DSB than a BB. It kills off all the algaes and allows bacteria from inside the rock to expell all the PO4. The critters you speak off to process waiste is the bacteria. Cooking the rock does NOT kill off this bacteria... nor does it kill all the "life" on the rock. Rocks will shed. The problem is we can't determine how much because we dont know what is actually built up inside it. Thas why to me it is vital for a DSB to have Rock that is a clean as possible.