Bare Bottom vs. Sand

That was quite complex. Of equal scientific merit, when it comes to the aesthetics of the debate here, I personally, me my own self, find certain Bare Bottoms, for example, e.g., thus pertaining, to i.e., that of my special "lady friend," to be quite pleasing to the visual sensorium.

Further, I personally have found that sand on one's bare bottom can be quite irritating, sometimes outright itchy. Is that due to those bristleworm thingies I read about?
 
It seems that we have to have SOME way of denitrifying our tanks; we either do lots water changes, run a DSB (remote or local), add plant life, or put a metallic catalyst within your tank. All methods are likely valuable. Let’s make the following conclusions based on our observations (backed up by the science): DSB’s either remote or local are very useful for denitrification. The problem with Baja’s BB tank-that lost life and grew full of algae-is that without a local DSB and relatively poor circulation there was likely phosphate and nitrate buildup within that particular tank. This does not go against the use of a remote DSB, what it does say that if you have a BB tank, you must have enough of the water column circulate past and over the remote DSB to remove enough of the nitrates in the tank. There seems to be a relationship between the amount of bioload (nitrate) your tank is producing, the method you denitrificate (algae, water changes or DSB- local or remote), and the ability of the water column to reach the point of denitrification. That is why in this discussion there are as they say; more than one way to skin a cat. Baja’s experience was likely based on multiple parameters and should not be used to wholly discard the utility of a remote DSB. Infact, there is a tremendous amount of support for remote DSB and the experience of many is that it can effectively reduce nitrates, but in all the setup’s described on the thread mentioned in my previous post, a good portion of the circulation does in fact pass over the remote DSB via adequate circulation.

It would be interesting to know; Baja, did you have different nitrate and phosphate readings in your tanks? BB vs DSB-when you experienced the loss and algae overgrowth? I think this info would seal the deal.
 
IF the theories on why many hobbiest test kits routinely measure 0 trates and PO4 when obvious algae is growing are correct; ie the nutrients get taken up before they can be tested, it would seem to argue against the remote DSB being as good for nutrient removal.

I also think one salient point on DSB's that pertains well to remote DSBs is you need lots of meiofauna to successfully run a DSB. Diverse meiofauna. It's very tough to get. Believe me I know. I've seeded my bed 3 times. I know Bajabum gets his from deep down in the ocean bed. Most people don't have that luxury. Plus many of these fauna are self limiting and will die out. Third IIRC Shimek was quoted as saying something like 50G is a minimum for a successful DSB.

I think you missed one or 2 ways to deal with de-nitrification. First one base theory of BB is lots of flow and heavy wet skimming(I know it was alluded to earlier). Get the junk out BEFORE it decomposes and creates ammonia and trates. I don't think it's as bad as Richard thinks. A good small skimmer and good flow does not have to be expensive or need a nuclear reactor to run.
Second is a probiotic system where you count on bacterial growth to consume nutrients. Again have wet skimming to take out the bacteria. I don't use either as a pure method although I do use lots of the BB methods in my tank. I have accidentally used probiotics and my tank was super clear with no diatom growth for 2 weeks(just been too chicken to do it again on purpose this time).

I love my sand for the extra diversity. I have lots of good flow and undertow. I skim with a Deltec. I seed it. I have a pistol shrimp that keeps half stirred up. Light bioload. And I still worry my sand bed is a time bomb. I guess I have my doubts about remote beds but I think this is a very interesting discussion.

edit: I know Bajabum has 700G in his system. I'm thinking more along the lines of what most people here would be able to do.
 
Dang remember K.I.S.S. mentioned earlier? Been running a DSB in a 20H for over 2 1/2 years. Yeah, ya gotta change 1/3 sand out once in a blue moon. Hint: try to pull as much of the concrete-like fused sediment from the bottom. Yeah, lots a critters (the GOOD bristleworms, for instance), nassies and what-nots are a necessary. But this is where I get into darn near fist-fights with certain LFS personnel on: keeping the bed undisturbed. The first time I went into AT I almost permanently walked out, because I wanted an A. phalena (Dragon Goby). I was asked, rather snobbishly, "Why do you want one of those destroying your sandbed?" I walked out. Anyway I ended up with one and, yes, they will toss sand about even after taking to flake/frozen food. That's the freakin' point. You put live rock in - it denitrifies. Regardless of sand system used, DSB, Plenum, or remote: denitrification will take place. With an undisturbed plenum, it's probably quantifiable and if you want a Zen garden thing (perfectly flat sand w/rocks in the middle), I think a plenum is the only "safe" way of doing it. Jaubert's theory is chemically sound.Sandsifter or not, anaerobic bacteria is going to grow in your tank. Everyone talks like it takes years to culture this stuff. If you believe that, and have an established canister filter hooked up to a tank, unplug it for for 6 hours and then turn it back on. Enjoy the stench while you watch yer livestock curl up & die.

No sand sifting organism is going to turn over so much of your bed that anaerobic bacteria is going to be completely destroyed. The idea is to prevent a large killing H2S04 pocket from forming. Some of the anaerobic sand gets flipped up to oxygenated H20 and the aerobic bacteria grows rather rapidly, meanwhile aerobic bacteria covered particles get flipped, too. Vice-Versa. Honestly, I believe (sorry - got no data on hand) with an aggressive sand-sifter, there wouldn't be time for a "bomb" to be built. Even with those little areas they miss for a while, they'll be so small any H2S04 build-up is going to be minor and bubble up rather harmlessly.

As-a-matter fact, in freshwater planted tanks where bottom heating cables are used, the small anaerobic pockets are considered a bonus to the system and are deliberately created for denitrification (actually why they havent been developed for marine systems, I dunno - they're very low voltage.)
 
This is one of the more useful BB vs. DSB discussion I have read. Everyone is working to make good points and learn instead of throwing stones.

Keep this going.
 
I believe most of the time people talk about sand sifters destoying the sand bed it's not because of the aerobic/anaerobic zones but rather they will eat all the meiofauna.

The time bomb I refer to is the waste is not all processed in a sand bed. One of the advantages of a black sand bed is I can see all the pockets of detritus that just sit there under the surface and do not go away. For SPS keepers that's a ticking time bomb.

I think one point that's been missed is what you are trying to keep. FO, softies, sps.
 
<a href=showthread.php?s=&postid=9698187#post9698187 target=_blank>Originally posted</a> by Philwd

The time bomb I refer to is the waste is not all processed in a sand bed. One of the advantages of a black sand bed is I can see all the pockets of detritus that just sit there under the surface and do not go away. For SPS keepers that's a ticking time bomb.

I think one point that's been missed is what you are trying to keep. FO, softies, sps.
Click to expand...

Phil,

If you have lots of snails, worms, starfish, this waste should be gone pretty quickly right? I know that I have tons of worms and a large starfish that I think take care of this. Most sea cucumbers eat mainly algae but do you think they can care of the waste that sits on or near the top of the sand bed. Mine is white so I don't see much I guess.

BTW, what kind of probiotics did you use? I am thinking of going with the blue coral method.
 
I agree Phil. I have gone back to using Sea Clone skimmers in my systems. But I only want to control my algae growth, not eliminate it. I want bugs growing in all my systems The BIG thing I have noticed is water quality is more dependant on individual tanks rather than system water, which points to substrate as the controlling factor. The use of bacteria based fauna in the sand allow me to maintain a much higher biomass. My systems are so active you will never get a phosphate/nitrate reading on a test kit untill it totally crashes. It all gets eaten in a bloom of one type or another. Phosphate/ammonia removal issues are also competeing issues. In order to have fry survive, I must have a very reactive system that removes pollutants in hours, not days or months. I have found this thread very helpful. I am going to try and put it together in a web page we all can edit, because it is a complex issue that is the root of long term success to any system.
I can definitly see the advantage of a remote DSB to maintain a small system. As an example: I am using 300 gal of support tanks to maintain a 180 gal sps/lps/fish/anomone tank. A five gallon bucket hooked to a 20 gallon makes a lot of sense.
I can not use PS because of the small fish I have. They require microfauna which feed on the suspended organics.
Thanks Jaredloo for puting the science up. That makes it easier for those who don't design sewer treatment plants.
DSB no oxygen, Do not disturb. Bacteria only.
DSB with oxygen, bacteria based Fauna do best being disturbed.
BB with heavy Protien Skimming removes microfauna.
Algae beds algae based fauna, slow at removing phospates/ammonia, can be out competed by cyno/slime algae. As a note, the tank that had the cyno problem has the highest water turn over in the system.
 
Sorry I didn't put the source up. Here is the link to wikepedia for denitrification. If you really want some chemistry reading, follow the link to the source that wikepedia pulled from. I am studying it now but it will take a while, there's a ton of info there, right down to the nitty gritty. It's the PDF link to Zumft, W.G. (1997): Cell biology and molecular basis of denitrification.

Wikepedias definition of denitrification:http://en.wikipedia.org/wiki/Denitrification

Maybe some of the Chemists and Doctors can help us all understand all of this. Please make your comments all of you with MD's and PHD's.
 
You have the chemistry right. My father designed sewage treatment so I grew uo on it. I take it for granted.
This is what I see.
DSB no oxygen, Do not disturb. Bacteria only. NITRATE REMOVAL ONLY
DSB with oxygen, bacteria based Fauna do best being disturbed. EATS ORGANICS requires biomass removal
BB with heavy Protien Skimming removes microfauna. MECHANICAL ORGANIC REMOVAL ONLY
Algae beds algae based fauna, slow at removing phospates/ammonia, can be out competed by cyno/slime algae. EATS NITRATES/PHOSPHATES requires biomass removal
CYNO/SLIME algae beds rapid cycling, will return organics to water when dark. EATS ORGANICS, NITRATES/PHOSPHATES requires biomass removal
 
Good summary baja. Would you mind elaborating on each of those summaries so that we can be sure we all understand exactly what you are concluding. Thanks.

Also, I have posted a link to our thread on the Chemistry Forum for Randy to take a look at. Hopefully he puts in a comment or two as well.

http://reefcentral.com/forums/showthread.php?s=&threadid=1095234

I agree with Van, this is a good thread, and I'm glad there is no lashing out at eachother going on, but rather, it is a science based objective discussion. Thanks everyone for your input thus far and keeping it objective.
 
I thought so too Van. It seems the detritus sinks through the sand and forms pockets 1-2" down. At least in my system. Sometimes my clowns or pistol will hit one and then snowstorm city. Then I get bad diatoms for a couple weeks. Makes me wonder about a couple years down the road.
I have lots of worms, bristle, spaghetti, huge 18" worm, lots of ceriths, big black brittle star, pods galore and had tons of mini brittle stars(something ate them all). Even when I still had all the minis I still got pockets. I do see occasional worm trails into the pockets but they are never completely consumed (In fact I see old trails fill up with detritus). A cuc may work better. Not sure.

I think sterile systems are just that..too sterile. Just personal preference Algal growth is natural. We play on this knife's edge of meiofauna diversity and water quality. I think Richard's work is great.

The mention of probiotics was a general reference to encouraging bacterial growth through adding a carbon source. In my case I added a gluconate based Ca additive. Got a huge bloom(duh). But it sucked up all the nutrients. Been thinking I got lots of the stuff left. Maybe do small doses once/week.
 
What I don't know is what a no oxygen DSB does to Phospates. So someone chime in. If I take nitrates out without there associated phospates, I am going to swing a system towards cyno production. I unfortunatly know how to do a cyno scrubber.
 
I have put together a table on the following web page:
http://users.commspeed.net/bajabum/LiveStock/Waste/Waste Processing.htm
What stood out to me is that only one method addresses waste processing before it becomes dissolved in the water column. That is a DSB with oxygen which is consistent with my system observations.

I will elabrate on details from question I see. I have provide links to what I have saved for future editing so far at the bottom of the page. I can add more if I missed something.
 
Just a word on the meiofauna and sandsifters. The beauty of QT is you can (I have) get these guys to experience the joys of the All-American diet. Oh yeah, processed food, baby - processed food. Once mine got a taste for the ease of hunting dead mysis and flakes, sandsifting, or sand tossing, became more of a hobby (although a few nice crunchy cichlid food pellets stuck around the den always is a fun treat). I always had (and have) plenty of pods, bristleworms, snails etc. in the bed.
 
Regarding phosphates: Can't you use iron exchange, (no I didn't say ion, 'tho there's something to that later) like Phos-X on such a system. You could use a polyfilter to get the iron ions out, or it's possible (does anyone have info?) that some of the "desirable" macros in Rhodophyta would utilize them (also probably some of the phosphates, too). JMHO, but a big clump of Flaming Dragon's Tongue would enhance any reef set-up!
 
Really great stuff Baja and everyone. Thank you. I think once the science is laid out you have to decide how to weigh each piece of information for its "real life" contribution to the chemistry of your particular tank. I also have the feeling that once it is all laid out and we determine the relative weight (in as much as it is possible without a huge R & D budget) of these various biologic process' on nitrogen and phosphate balance and the processing of organic waste, the conclusion again, will likely be that it is a matter of personal preference and that there really is no one absolute best way to manage your tank. Or perhaps that the best way to approach this, is to find a way to apply all of these process within one system to get the safest and most balanced (buffered) system. That is to say, if you want additional anaerobic denitrification, attach a remote, undisturbed DSB to a system that already has a main tank with a dynamic DSB full of critters and aerobic metabolism with breakdown of biomass. Seems likely that in the ocean, the very deep sand bed has both pockets of each type of sand bed; providing both aerobic and anaerobic metabolism. Mimicking the ocean is something that is very difficult and it is truly our ultimate challenge. I have an idea; we could plumb all of our tanks together in Arizona through the sewer system. Think of the biodiversity. We would never have to worry about animal losses because for every animal lost in one tank another would be born or prosper in another tank. I think our problem here is that utopia; the ocean, is impossible to mimic on dry land. It is very difficult to have everything. And since having the diversity of the ocean is the only way to achieve TANK NIRVANA we will ALWAYS be left imperfect in our efforts. What a great hobby! The carrot is always within sight but can never be reached. And, finally to make any conclusions as to what is "better" can only be met with the reply, "yeah but it still doesn't do this:________________. And, you will always be able to say that this other system does this: ___________________, so how can this system be better? One will always be able to make that statement. Breaking up the ocean into little pieces can never be as good as the entire ocean floor as one unit. For every ying there is a yang. If you want a BB to support SPS, then you have to augment circulation and skimming because without the aerobic conditions of a dynamic DSB with critters, you will not be able to process organic waste in your main tank. If you over skim your SPS might not see the nutrients it needs. So you will need to slow down your skimming to maintain a certain amount of nutrient in your water column, and if you do that without a DSB, you are bound to develop higher levels of nitrate and phosphate, so you will need a remote DSB to handle the excess.
 
Here! Here! Well put. That is the same conclusion that I have come to. When all is said and done, it just comes down to preference. The whole carrot being out of reach is exactly what is fascinating about this hobby. We are constantly striving for better ways of reefkeeping, and constantly striving to keep our reefs as close to the natural ocean as possible, but it really is the elusive white rabbit.

Really makes you appreciate the wonder of the ocean in all it's splendor doesn't it. Such an amazing, beautiful, perfect system of symbiotic life, and self renewal. There really is no way to mimic the ocean unless we create another world like the beautiful one we live on that is just the right distance from it's sun, in just the right proportions so that is stays in that particular orbit instead of flying off into space or come crashing in to the sun. A world with water and carbon and oxygen and other elements needed to sustain life. We would need to create tides, a moon, plant the world, populate it with animals of all different species, add weather systems, and the list goes on and on. I don't know about you guys, but I tip my hat to the Man Upstairs.

I'm glad we have this beautiful world and to bask in it's multiple fascinations including the ocean. I'm glad I can have a little piece of it, even though my piece is flawed in comparison to the real thing, right in my own living room. Thanks everyone.
 
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