Gas Gas Gas

[cajamajo]

I have spent some going through past threads, and I want to make sure I underestand this right. I have around 3" of super naturals white marine sand. My cycle ended several weeks back. I have been getting the nitrates down slowly. They are now at 10. I am having gas bubbles rising from the sand. If I understand this right, and correct me if I am wrong. The sandbed it providing a oxygen deficient condition so that anarobic bacteria can convert nitrates into nitrogen gas that is excapeing from the sand. This is a natural method of nitrate removel. I have ordered 50 nassarius snails to keep my sand clean. My question is what affect will they have on the process currently going on. Thanks

 

[1journeyman]

Depends on the depth of your sand bed.
A sand bed over 4 inches deep allows for anearobic bacteria to break nitrate to nitrogen gas.
The snails will be good to keep the top layer of sand stirred up. That's crucial.

 

[colourmop]

yeah i noticed lot air bubbles start to form around 1-2 inch depth of my sand bed (5 inch total) i think those are nitrogen gathered from deeper area. go bacteria go!

 

[saltn00b]

yea you have what is called a DSB - Deep Sand Bed, where the critters in the sand will eventually be able to break the trates down , similar to the process you would find in a fuge. It is my understanding that Plenums are very good for running tanks with DSB's but i dont know much about how to implement them. Plenums are basically pockets of 'dead' water under the DSB that allow for the full cycle to complete. you can do searches on this on the web. It may also take a fair amount of time for your sand bed to accumulate a good variety of biologic matter. Especially if its new. Consider seeding your bed with a scoop of a friend's mature sand or something.

 

[cajamajo]

A friend did give me a bag of sand from his fuge when I started. my tank is starting to do great. It was worth the wait.

 

[mikeyjer]

Originally Posted by 1journeyman
Depends on the depth of your sand bed.
A sand bed over 4 inches deep allows for anearobic bacteria to break nitrate to nitrogen gas.
The snails will be good to keep the top layer of sand stirred up. That's crucial.
This is a debatable subject!!! It doesn't need 4" of sandbed to occur in my opinion, my tank can prove that.....But I agree with the snails part.... :happyfish

 

[1journeyman]

Originally Posted by Mikeyjer
This is a debatable subject!!! It doesn't need 4" of sandbed to occur in my opinion, my tank can prove that.....But I agree with the snails part.... :happyfish
Well, abnormalitites in individual tanks certainly occur. That can't be argued. Having said that, outside of individual success can you point to any research countering my statement? I'm always willing to be corrected!
Reef Invertebrates by Calfo and Fenner, pg 36.: "beds of 1" to 3" are the most popular and yet precarious. When maintained properly, they offer swell advantages with little trouble. If neglected, however, they can quickly be problematic (largely by prolonged neglect and nutrient accumulation).... Aquarists with a decided microbial preference should commit to a more shallow or deeper bed of sand as neccessary."
And, same page: "Sand Bed strategies require sufficient depth of substrate to support denitrifying facilities. With increasing grain size, the penetration of oxygen rich water increases and so does the need for more sand at depth. Sugar fine sand should be applied at a depth or more than 3".... Aragonite has a "half-life" of 18-24 months... For this reason, aquarists seeking optimum nitrate control are advised to resist being frugal and apply honestly deep sand beds of more than 3" with 4"-6" as a good start...."

 

[saltn00b]

as i understood and just posted in another thread:
LS comes in a variety of grain sizes, from large and chunky, to super fine, silt and even clay / mud grain size.
the superfine silt is better for Fuges and Nitrate fixing and and the larger size is better for pods and other organisms.
you wont have any nitrate fixing unless you have a DSB - deep sand bed, which should be at least 3" - 6" deep , depending on tank size.
if you do not want a DSB than i personally recommend a very light layer of substrate , about 1/2" to avoid anaerobic gas bubbles forming
and throwing your trates off, as has happened to me. You want to avoid that 'no-man's' zone of 1"-2.5" where this will be the case.

 

[cajamajo]

I went and measured my sand bed to be sure of the depth. It is 3 and a half to 4 inches in places. My nitrates have been dropping and continue. My cycle has ended the trates started out at 40 and now are down to below 10. I am still getting bubbles here and there. The sand is very fine. It is not live sand it is white aquarium sand A friend gave me a bag of sand out of his fuge.
ammonia 0
trites 0
ph 8.2

 

[mikeyjer]

Originally Posted by 1journeyman
Well, abnormalitites in individual tanks certainly occur. That can't be argued. Having said that, outside of individual success can you point to any research countering my statement? I'm always willing to be corrected!
Reef Invertebrates by Calfo and Fenner, pg 36.: "beds of 1" to 3" are the most popular and yet precarious. When maintained properly, they offer swell advantages with little trouble. If neglected, however, they can quickly be problematic (largely by prolonged neglect and nutrient accumulation).... Aquarists with a decided microbial preference should commit to a more shallow or deeper bed of sand as neccessary."
And, same page: "Sand Bed strategies require sufficient depth of substrate to support denitrifying facilities. With increasing grain size, the penetration of oxygen rich water increases and so does the need for more sand at depth. Sugar fine sand should be applied at a depth or more than 3".... Aragonite has a "half-life" of 18-24 months... For this reason, aquarists seeking optimum nitrate control are advised to resist being frugal and apply honestly deep sand beds of more than 3" with 4"-6" as a good start...."
I have read those as well, not saying your wrong about anything, but like you've said, things do happen in each individual's tank. There's serveral others that have the samething happening. So that's why I put it's a debatable subject and my tank can prove that it can happen without having 4"+ sandbed.

 

[1journeyman]

Cool Mike. Like I said you clearly have a successful tank so I'd never try to argue with ya on that!
What type of live rock do you have? Could it be that it's exceptionally porous and therefore you're getting a lot of nitrifying bacteria in your rock moreso then in your sand?

 

[mikeyjer]

Originally Posted by 1journeyman
Cool Mike. Like I said you clearly have a successful tank so I'd never try to argue with ya on that!
What type of live rock do you have? Could it be that it's exceptionally porous and therefore you're getting a lot of nitrifying bacteria in your rock moreso then in your sand?
I have Hawaiian base rocks and Fiji live rocks. :happyfish

 

[cajamajo]

I have fiji rock. I am getting bubbes big enough that when the hit a ph it blows tons of small bubbles. I dont know