Dont flame me for this but im starting a freshwater tank and wondering....

[tellico tornado]

I know not to put live sand in my freshwater tank but is it ok or does it serve the same purpose to have about a 4" Sand Bed (lets say southdown sand) in a freshwater tank? Will that sand soon become live FRESHWATER sand? Just wondering. Ive had so much success with my saltwater DLSB i was planning on trying the same thing with my freshwater tank. If for some reason any of you have tried this or know anything about it please let me know.....

 

[luke]

In theory it could work... but you need creatures to take care of that substrate. Denitrafacation still holds true in FW. If you don't have creatures to take care of the substrate, it will have zero oxygen which will lead to hydrogen sulfide build up (I beleive it is Hydrogen sulfide [someone correct me if I am wrong ]). This of course is bad!
Luke

 

[wamp]

Hey luke, you want your lower level of your substrate to have Zero O2. Thats how it denitrifies. It is anareboic. If you put too many creatures in your substrate and they dig deep it will add O2 thus becoming aerobic and actually hendering denitrification.
Just thought I would throw that in there for ya.
As far as a freshwater DSB... Never heard of one. But who knows?

 

[wamp]

By the way. If I had a lighter I would burn your a@# for changing to a FW tank.. Thats like painting over the Mona Lisa with neon colors..
But, to each his own.

 

[kung fu]

Actually didn't I read in "Live Sand Secrets" that DSB's and Plenums actually may perform even better in freshwater aquaria? I think Goemans talks about that the data isn't really in yet but the initial reports are excellent...
Peace...

 

[luke]

Wamp, you obviously don't have a real grasp of denitrafacation. Yes it does need low O2 levels, but if there is zero O2 down there hydrogen Sulfide will develop (which is highly toxic and smells like roten eggs). You are correct that if there is too much O2 then denitrafaction will be hindered, but it is a balance.
Just thought I would throw that in there for ya <img src="graemlins//yeahright.gif" border="0" alt="[yeahright]" />
Luke

 

[tellico tornado]

Thanks for the response guys.... oh and by the way.... im not "changing over" from salt to freshwater. Im keeping my saltwater, and im setting up a freshwater for my parents. They would obliterate a saltwater tank
And i will keep you guys posted on it. If it works great and if it dont ill let yall know so you dont try it... <img src="graemlins//freak.gif" border="0" alt="[freak]" /> <img src="graemlins//eek.gif" border="0" alt="[eek]" />

 

[wamp]

Luke,
Perhaps not a grasp.. But, I do know that anaerobic bacteria grows and lives without the presence of O2. (or in very little O2) Perhaps you should read this link below and, if you wish I will send you more so you can validate the source. Now the whole statment I made was if you have to many sand critters you WILL disturb your DSB and that will void the whole point of having a DSB at all.
<a href="http://web2.iadfw.net/westcott/Nitrate.html" target="_blank">http://web2.iadfw.net/westcott/Nitrate.html</a>
Anaerobic bacteria, as I am sure you know, is the bacteria that actually does the denitrifing in your tank. This is why Wet/Dry do such a poor job of breaking down nitrates into free nitrogen. Perhaps the Hydrogen sulfide as you call it is in response from the anaerobic bacteria coming into contact with O2?

 

[wally]

I have been thinking about trying them same thing. I would however use quickcrete or some other type of quartz/silicate sand as southdown will make the water get very hard. Get some malaysian trumpet snails. They are white to grey and are shaped like ice cream cones. They burrow into the sand during the day and some out at night and make a great clean up crew. They will keep you substrate nice and clean.

 

[luke]

Wamp- Anarobic bacteria do not function in zero O2. It is a balance (as I stated earlier). If you don't have the creatures to maintain the sand bed then it will develop pocket of zero O2. This will cause hydrogen sulfide buildup. Again this is toxic. I am not suggesting that you have so many creatures that the sand bed has ample O2, just that if O2 levels go below a certain point, there will be problems. As for evidence of this:
Refer to the Reef Aquarium Vol. 1 Page 146 It states :
"The confined water behind the partition in these reactor tanks has an average oxygen concentration of 1 mg/L. If it should rise above 1.5 mg/L, denitrification is incomplete, producing exess nitite. If it should fall below 0.5 mg/L, the production of toxic hydrogen sulfide occurs."
Also if you look at your own link:
"Should you disturb these areas, you will have disrupted this process. You may also be releasing toxic elements like hydrogen sulfide, nitrites, ammonia, and nitrates."
Zero O2 implies 0 mg/L. Obviously 1 mg/L is far below the main aquariums O2 level (which is around 7 mg/L) As I said it is a balance.
Luke

 

[fshhub]

i am not getting into the chemistry debate, since i am no chem major, but i do want to ask you guys to cut out the swearing, LOL,
"FW" IS FORBIDDEN terminology, lol(just kidding guys)
i can't see why you could not use sand in a fw tank, good luck
jsut keep us posted, i would really like to know how it works out too, i have often wondered this question
oh and back to the chemistry debate, anaerobic bacteria by definition means bacteria that grows in the absense of o2, however, you do need to stir the sand some, so the nitrogen can escape, otherwise it will become compacted and the nitrogen will not escape, as for hydrogen sulfide, i have heard reference to hydrogen sulfide pockets in sand before, but cannot recall the spec on it's tak in an aquarium, but i am sure that it is toxic in a tank

 

[fshhub]

oh yeah, my wife just pointed out, if you are using southdown, ther may be a minor prob there, aragonite(or southdown), has buffers in it, where as if your ph gets too low, it will break down and raise it (some), and same with calcium
so, you may want to use a different type of sand other than aragonite, or at least explore this issue further before buying the sand you will use

 

[jrruss]

actually i live beside a river here in my home town. I know where theres a really long stretching sand bed in the river. I was planning on digging up some of that to use. So it should be already buffered to freshwater spec right? <img src="graemlins//bah.gif" border="0" alt="[bah]" />

 

[lordofthereef]

i don't think thats a good idea since there may be chemicals and stuff in that river that are no good for your tank. think about it!

 

[jrruss]

good thinking lordofthereef
and if your wondering im at work and the other guy that works with me uses this board too, im under his name looks like oh well...

 

[bt_1999_66]

Luke & Wamp.....
Don't Stop now....
This really is some of the most informative reading that I have read on Nitrate build up/Denitrification...
You guys are doing great.... Thanks...!

 

[wamp]

I guess I will agree to disagree with your statment and leave the debates to the chemistry proffesers. I still say anaerobic means without O2. The bacteria in the sand is anaerobic. If you can send me info on how you can have anaerobic bacteria in the pressence of O2, I will be more than happy to read it.. And I have read the statments you wrote earlier.
by the way to the person who said you need to stir your sand, Nope Nope Nope... You do not need to disturb The BOTTOM layer of your DSB. Now the top 1/2 or so will be ok to be disturbed but the bottom must be left alone to work.

 

[josh]

Hi all, ok here's what I know and yes I do have a degree in chemistry. The term anaerobic by definition means without oxygen. I won't go into the whole biochemisty of it, but the microbe uses nitrate to accept the electrons that are released during phosphorylization ( energy production by means of breaking down simple sugars down the electron transpost chain yielding ATP - energy ) instead of oxygen as we do. Got it So you see why oxygen is not needed, thus anaerobic.
-Josh-

 

[aquaman2]

you might want to keep an eye on your ph depending on what your gonna have in it, because the sand will most likely buffer your ph higher then you want it.

 

[luke]

Josh and Wamp and others? : I am not saying that anaerobic bacteria need O2! I was only pointing out that in our aquariums, if they live in zero O2 there are problems that arise. Hydrogen Sulfide in an inclosed space can cause serious issues. Anaerobic bacteria don't need O2 to survive, because they don't use it as fuel. Aerobic bacteria do need it to survive, because they do use it as fuel. As someone stated earlier, anaerobic bacteria are far more efficient than there anaerobic counterparts. Thus if O2 levels rise above a certain point, then denitrafacting bacteria are overrun by araebic bacteria.
The issue here is simple: I am simply stating that in an aquarium envirnment there is balance between low and high amounts of O2 for anaerobic bacteria to survive and not have biproducts created (either as a result or otherwise).
Luke