DSBs and Nitrates
 

Recently I've read a number of posts here and on the ReefTank saying that deep sand beds cause nitrates.

I have no problem with nitrates in one lightly stocked tank with a very deep dsb and minimal filtration. Yet I do have nitrate problems in my larger tank that until recently was overstocked and is now stocked with a few large fish with hefty appetites. So it seems like the fish and fish food are responsible for my nitrate problem, not the dsb.

Also, these comments run counter to articles favoring DSBs, such as one by Bob Fenner, author of and co-author of Reef Invertebrates. The following quotation is from an article on DSBs on at [url]http://www.wetwebmedia.com/deepsandbeds.htm[/url]

"One of the principal benefits to deep sand bed methodologies is the potential for natural nitrate reduction (NNR). The speed and extent to which a DSB can reduce nitrate in an aquarium amazes many aquarists… especially those that have struggled with nitrate control for any length of time through other means. The benefits to an established tank with the upgrade to a DSB are apparent in just a few weeks with potential for complete nitrate reduction (to “zero�)!"

I am curious as to the basis of the recent anti-DSB comments. Is there research proving that DSBs cause nitrate accumulation? Where is this information coming from?

Thanks for any information you can provide.

I have not seen any research yet on this and run dsb on my reef tank. I think it is personal preference.

I also haven't seen any research on dsb crashing and would be very interested to read something more than anecdotal evidence.

I was just searching WetWebMedia.com for more info and found the following by Scott F. Comments?

"I think that is a speculative argument based on largely anecdotal evidence. In fact, thousands of hobbyists, myself included, have maintained DSBs for years without any problems whatsoever. I think that the "DSB becomes a nutrient sink that will crash your tank" argument is based upon several people having bad experiences and then going wild on the popular reefkeeping message boards touting the detriments of DSBs. A properly developed, well maintained DSB in a tank with overall good husbandry techniques is an excellent way to successfully maintain a reef system. The key is attention to proper husbandry. DSB's are not a miracle, but they are not recipes for disaster, either. Attention to water quality, feeding, etc., vital in any system, are also critical in a DSB-based system."

I believe there’s nearly universal agreement that a properly maintained DSB will provide an environment for bacteria, which reduce nitrate. The only circumstance I can think of, where a DSB would be a nitrate source, is if it’s aggressively aerated (like us old-timers use to do with under-gravel filters). But, I don’t think very many people use UGFs now.

Most of the anti-DSB comments come from people, like myself, who never figured out how to get them to work properly. They become traps for phosphate-rich material. The phosphate then leaks back into the water to fuel algae growth.

If you have animals in your tank, which are adapted to grow in a nutrient-rich environment (like a lot of soft coral), it’s ok. If you have animals in your tank, which have adapted to grow in nutrient poor conditions, they may struggle when competing with algae. Any injury to the coral may provide an opportunity for algae to take over, and the coral may never recover.

[QUOTE][i]Originally posted by suzstephens [/i]
[B]I was just searching WetWebMedia.com for more info and found the following by Scott F. Comments?

"I think that is a speculative argument based on largely anecdotal evidence. [/B][/QUOTE]

It's not speculative or anecdotal when you know exactly how marine sediments work.

What [B]is[/B] speculative and what [B]is[/B] anecdotal is the assumption that marine sediments will act differently just because they are in a glass box.

[url]http://archive.reefcentral.com/forums/showthread.php?threadid=263482&highlight=Journals[/url]

I've tried researching those DSB crashes, and got some interesting results, although I'd like to hear from more people who have had a crash.

So far, all of them have set up the bed incorrectly (in one or several steps), which down the road led to a disaster.

I also like to think that the problem with DSB crashes is that hobbists know more than experts. :bigeyes:

Here's a relative novices take on the matter:

I ran a CC bed in my tank for about a year, for the last 8 months of that year it was beautiful. Levels at zero's, great growth and colors... then CrAsH. Nitrates thru the roof.

Read up on Bomber's BB thread. Sounded great. Installed a 29g sump and an ASM G-3 on my little 46g tank. You'd think all would be perfect... WrOnG. Nitrates rising 5-10 ppm/wk... steady. I have been doing biweeky 50% water changes for the last 6 months just to keep my SPS alive.

I went to a DSB and a DSB fuge with a DSB in-a-bucket in a section of my sump. [i]At this point I would kill for six months of reasonable stability[/i] If it crashes in a year or two or three, I could care less... it's a relatively easy fix and would require only a couple of months to restart.

My point: I don't subscribe to any one method, I just want a succesful reef. If you are going to try BB... here's what they don't tell you:

1. Use less rock and you probably better cook it.
2. Make sure any surface the rock touches can't trap ANY waste.
3. You can have NO waste/detritus build up... anywhere.
3. Figure 75x [i]plus[/i] in tank turnover. [I had 50x :(]
4. You probably need an oversized Beckett... you'd think an ASM needlewheel designed for a 240g would suffice for 60g... uh-uh.

This is just my take and honestly it's mostly just to vent as I'm EXTREMELY tired of water changes :lol: Happily I'm already seeing an improvement in NNR and I can quit being a slave to my tank :rollface:

[QUOTE][i]Originally posted by romunov [/i]
[B]So far, all of them have set up the bed incorrectly (in one or several steps), which down the road led to a disaster. [/B][/QUOTE]

That not true at all. Even the DSB experts tanks crashed for one reason or the other.



[QUOTE]here's what they don't tell you:[/QUOTE]

Sure did. LOL Where do nitrates come from? You left out wet-skimming BTW.

Please provide a link detailing DSB set up and use..

Thank you

Albert

Here's a good intro...

[url]http://www.wetwebmedia.com/deepsandbeds.htm[/url]

[QUOTE][i]Originally posted by Weatherman [/i]
[B]Here's a good intro...

[url]http://www.wetwebmedia.com/deepsandbeds.htm[/url] [/B][/QUOTE]
I will check it out...Thanks

The environments most conducive to denitrification (turning nitrate in N2 gas) in nature are fine sediments (sand/mud) and "dead coral heads," in other words live rock. There have been a lot of studies on this, dating back at least to Odum and Odum in the 50's I believe. As many of the folks that dislike sand beds have pointed out, there is nothing natural about having fine sediment on a reef crest or upper reef slope. Unfortunately, it isn't easily possible to replicate any of the conditions here. It would take a jet engine to get the proper water flow (no exaggeration).

However, there is also nothing unnatural about finding the corals that grow on reef crests and upper reef slopes on reef flats, backreefs, and even in many lagoons. In these habitats, sure enough, fine sediments where a lot of nutrient recycling takes place are present. Like it or hate, on natural reefs nutrient recycling is necessary for the system to keep running, and the majority of this recycling is done is fine sediment.

I've seen all kinds of tanks work and all kinds fail. I really don't care if anyone uses a deep sand bed or not, but IME they work very well.

Best,

Chris

No argument here…

Depending on the types of animals you wish to keep, a sand bed may be desirable, or even critical to your success.

[QUOTE]. Figure 75x plus in tank turnover. [I had 50x ][/QUOTE]

It seems to me that "turnover" doesn't quite capture the context, rather it's in-tank water movement, which can be substantially increased by adding penductors (another point left out).

[quote] Even the DSB experts tanks crashed for one reason or the other.[/quote]
Yes, but we must ask ourselves, why did it crash?

I've probably read every DSB article there is on the internet... And made a list of the ones I think can help in one's understanding of how we think DSBs work. Available [url=http://gutfeeling.mine.nu/my/dsb.html]here[/url].

ones again i recomend the articles romunov has. i have read most of them and you can truly find almost everything you need to understand how a DSB works

[QUOTE][i]Originally posted by Dag [/i]
[B]It seems to me that "turnover" doesn't quite capture the context, rather it's in-tank water movement, which can be substantially increased by adding penductors (another point left out). [/B][/QUOTE]

I agree. My tank has 50x [i]in tank[/i] water movement... sorry if that wasn't clear. Good point on the penductors... if you have the right plumbing and space for them. I was also wet skimming with my ASM.

To reiterate: I liked BB and totally agree with the methodology. If I upsize i may try it again... the right way. I only wanted to point out if it's not correctly set up, it can be a nightmare.

[QUOTE][i]Originally posted by Bomber [/i]
[B]Sure did. LOL Where do nitrates come from? You left out wet-skimming BTW. [/B][/QUOTE]

...but you seldom spell it all out clearly in easy, short sentences for us common folk :rollface:

[B]That not true at all. Even the DSB experts tanks crashed for one reason or the other.[/B]

Of course, not all of those with DSB's may agree with you on what it means to crash. :lol:

If a reefer has not noticed a problem, but you conclude the DSB has crashed, did it really crash? :D

[QUOTE][i]Originally posted by Randy Holmes-Farley [/i]
[B]If a reefer has not noticed a problem, but you conclude the DSB has crashed, did it really crash? :D [/B][/QUOTE]

Is that a philosophical question?

Like, if a tree falls in a forest and no one is there to hear it, did it really make a sound? :D

[B]Is that a philosophical question?

Like, if a tree falls in a forest and no one is there to hear it, did it really make a sound?[/B]

It was meant that way, yes.

But Bomber has also claimed that my DSB has crashed, and I just didn't know it. If that can be true, then his definition of crash may be different than the average aquarist's.

[QUOTE][i]Originally posted by Randy Holmes-Farley [/i]
But Bomber has also claimed that my DSB has crashed, and I just didn't know it. If that can be true, then his definition of crash may be different than the average aquarist's. [/B][/QUOTE]

This, actually, is a good topic for discussion (although I'm sure it has been covered elsewhere before). Hopefully, it doesn’t diverge too much from the original intent of the thread.

What is a DSB crash?

Does a DSB start generating nitrates when it “crashes�?

(Since I’ve never used a DSB, I don’t have first-hand experience with them.)

[QUOTE][i]Originally posted by Randy Holmes-Farley [/i]
[B][B]Is that a philosophical question?

Like, if a tree falls in a forest and no one is there to hear it, did it really make a sound?[/B]

It was meant that way, yes.

But Bomber has also claimed that my DSB has crashed, and I just didn't know it. If that can be true, then his definition of crash may be different than the average aquarist's. [/B][/QUOTE]

I most certainly did not! Those were your words after I had posted something else. I just figured it wasn't worth getting into so I left it alone and didn't contradict you.

So, what’s a “crash�?

Is it… [b]Everything in your tank dies.[/b]

Or… [b]The environment in your tank no longer supports the animals you wish to keep.[/b]

I’ve been extremely fortunate to have never experienced the former. In the case of the latter, I either change the conditions in the tank or move the animals to a different tank.

When you experience the symptoms of high nutrients that affects the animals the system is required to house.

But then that's hard for people to grasp when they are led to believe that if they have phosphate or nitrate problems - they need to hook up a refugia, use a commercial phosphate remover, use a sand bed in a bucket, use a algae scrubber, etc etc.

If they are having P or N problems, that just means their system is dirty and will no longer store, pool, or sink those nutrients.

Plus 'crash' is very subjective. What one type of animal housed in the system might consider tolerable or even fine, another type of animal housed in that same system might have problems with it. So crash would take on a different degree depending on what the system is required to house.