Just Sand or Live Sand?

[michael r]

I'm currently on the look out for sand for my 90 gallon aquarium.
I was wondering:
1. How much sand would be appropriate?
2. Does it matter if I buy sugar-sized aragonite or live sand? I understand the live sand is better in that it's already 'cycled', but shouldn't the aragonite eventually become 'alive' as well because of my live rock?
Thanks,
Michael

 

[rbaldino]

1. Most people aim for about a pound per gallon. You should start there and see if it gives you a deep enough sand bed. At that point, it's up to you to decide if you want more for looks or function.
2. Yes, once established the sand bed will get seeded with bacteria from the rock.

 

[nietzsche]

Originally Posted by Michael R
I'm currently on the look out for sand for my 90 gallon aquarium.
I was wondering:
1. How much sand would be appropriate?
2. Does it matter if I buy sugar-sized aragonite or live sand? I understand the live sand is better in that it's already 'cycled', but shouldn't the aragonite eventually become 'alive' as well because of my live rock?
Thanks,
Michael
you can click on the button on the left side where it says live rock and live sand and they have a little calculator to figure out how many #s of sand you need. i have 1 inch sandbed in the 10, and probably a 3 in sand bed in my 28, but it's up to you to decide how much you want or wanna spend.
your live sand should eventually become live but it needs something like a cup of live sand or some live rock in order to seed it. i took a cup of my established 28 and added it to the 10. you an buy the carrib alive aroganite sand they sell at petland, it's not live at all though

 

[miaheatlvr]

Originally Posted by Michael R
I'm currently on the look out for sand for my 90 gallon aquarium.
I was wondering:
1. How much sand would be appropriate?
2. Does it matter if I buy sugar-sized aragonite or live sand? I understand the live sand is better in that it's already 'cycled', but shouldn't the aragonite eventually become 'alive' as well because of my live rock?
Thanks,
Michael
A Shallow sand bed consists of UP to 2" and a deep sand bed is usually up to 4"

 

[michael r]

Thanks for you help so far everybody,
and is it bad to have a sand bed at the 3" mark then?
Will the shallow sand bed and deep sand bed do the same things?

 

[nietzsche]

Originally Posted by Michael R
Thanks for you help so far everybody,
and is it bad to have a sand bed at the 3" mark then?
Will the shallow sand bed and deep sand bed do the same things?
i think the reason for using a deep sand bed is you have more beneficial bacteria to help out your tank, just like having more lr is beneficial. some people believe having a bare bottom tank is better since it allows the powerheads to keep the detritus suspended in the water until the skimmer picks it up. look at how much 3" is on a ruler and compare it to your tank. to me i thought 1 inch would be good for a 10, so i got enough sand to do a 1 inch sand bed. my 28 has a 3 inch sand bed, maybe a little more but it looks fine since its a larger tank

 

[1journeyman]

Originally Posted by Michael R
Thanks for you help so far everybody,
and is it bad to have a sand bed at the 3" mark then?
Will the shallow sand bed and deep sand bed do the same things?
3 inches is usually assumed to be in the "danger" zone of sand beds. It's too deep for criters to fully clean, and not deep enough for the bacterial benefits of a deep sand bed.
Go under 2 inches or deeper than 4.

 

[1journeyman]

As in all SW aquariums, keep detritus stirred up with brisk water movement and skim well.

 

[nietzsche]

Originally Posted by 1journeyman
3 inches is usually assumed to be in the "danger" zone of sand beds. It's too deep for criters to fully clean, and not deep enough for the bacterial benefits of a deep sand bed.
Go under 2 inches or deeper than 4.

If 3 inches is too deep for critters to clean, and not deep enough for bacterial benefits, then 4in+ is to deep for critters to clean but deep enough for bacterial benefits? If you say to go deeper than 4, than that means 4 inches is also the danger zone, right? jw, but what makes it more beneficial to add 2 more inches if critters still can't clean it?
also wouldnt make sense if this person had something like a nano tank, like a 10 and put in a 5 inch sand bed. lol. so this depends on how high and large your tank is.

 

[1journeyman]

Originally Posted by nietzsche
... but what makes it more beneficial to add 2 more inches if critters still can't clean it?
also wouldnt make sense if this person had something like a nano tank, like a 10 and put in a 5 inch sand bed. lol. so this depends on how high and large your tank is.
Anearobic bacteria must not be disturbed or exposed to oxygen rich water. The benefits of a deeper sand bed is that the anearobic bacteria breaks the Nitrates down into nitrogen and oxygen. That's why deeper is better than 3 inches.
Size of the tank is not really relevant. A Nano with a 3 inch sand bed can encounter the same problems as a 240 with the same sand bed.

 

[jtrzerocool]

so i have a 55g. i just bought 60 lbs of live sand! will i be ok with that shallow of a snd bed?

 

[michael r]

Assuming the sand bed is 2 inches, will I still be receiving the benefits of nitrate reduction?

 

[1journeyman]

Originally Posted by Michael R
Assuming the sand bed is 2 inches, will I still be receiving the benefits of nitrate reduction?
No.
Ntrate reducing bacteria is anearobic (lives in oxygen poor environment). That's normally found in sand 4 inches or more in depth.

 

[1journeyman]

Originally Posted by jtrzerocool
so i have a 55g. i just bought 60 lbs of live sand! will i be ok with that shallow of a snd bed?
How deep is it?

 

[michael r]

Alright, so let's say I'm aiming for 4 inches of sand.
Everything is expensive up here in Canada, so I'm sure you'll understand why I'm looking for some 'cheaper' options.
Using the calculator on this site, I need 140 lbs. of sand for 4 inches in a 48" by 18" aquarium.
If I bought 90 lbs. of sugar-fine aragonite and 50 lbs. of some silica sand from a hardware store (like Home Depot), would this work fine as well?

 

[nietzsche]

Originally Posted by 1journeyman
Anearobic bacteria must not be disturbed or exposed to oxygen rich water. The benefits of a deeper sand bed is that the anearobic bacteria breaks the Nitrates down into nitrogen and oxygen. That's why deeper is better than 3 inches.
Size of the tank is not really relevant. A Nano with a 3 inch sand bed can encounter the same problems as a 240 with the same sand bed.
I'm saying it wouldnt make sense to have a 5 or some small gallon tank and have a 5 inch sandbed. is there scientific research and data for this? I'd like to read it.

 

[1journeyman]

Sure. "Reef Invertebrates" by Calfo and Fenner addresses sand bed depth. In fact on Calfo and Fenner's webpage there are several articles on the topic. One quote states:
"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'm not sure what you are questioning. The presence of anaerobic bacteria in deep sand beds? Anaerobic bacteria breaking Nitrate down? Perhaps if you better clarify your question I can explain further.
I agree that a 5 inch sand bed in a 5 gallon tank would be extreme. This means you need to get a bigger tank if you wish to have a deep sand bed. It does not reflect on the functionality of a sand bed.

 

[michael r]

Originally Posted by 1journeyman
I'm not sure what you are questioning. The presence of anaerobic bacteria in deep sand beds? Anaerobic bacteria breaking Nitrate down? Perhaps if you better clarify your question I can explain further.
Not sure if this question was directed to me or not, but yes, I want to know if the denitrifcation will occur in a substrate other than aragonite, like silica sand.

 

[1journeyman]

Originally Posted by Michael R
Not sure if this question was directed to me or not, but yes, I want to know if the denitrifcation will occur in a substrate other than aragonite, like silica sand.
No, response was to another poster.
Research silica sand. I'm not a fan myself but some folks have used it.
Occasionally you can find aragonite sand at local hardware stores. Do a search for the "vinegar" test. Brands that I have used are Southdown and Yardright. I believe Old Castle is another sand from same company that is safe.

 

[nietzsche]

why is it that 3" is the danger zone? who tested this and why? what if you dont have anything that disturbs the sand?
"Another shortcoming of under gravel filtration is that it does not have the ability to convert nitrates into nitrogen gas. This is because the water which is passing through the under gravel filter is actually moving relatively fast and is high in oxygen content, for this reason the anaerobic bacteria which are required to breakdown nitrate to nitrogen gas do not carry out this function as the conditions required are low oxygen and slow moving water.
When a sand bed starts to get deeper than 2+ inches then anaerobic areas will start to form. Anaerobic areas in a sand bed are areas which are very low in oxygen content, this is because the oxygen is being used by the aerobic bacteria above. Water flow through these lower areas occurs partly because of the burrowing activities of the organisms which live in the sand but is primarily due to an activity called diffusion. All fluids have a tendency to perform diffusion and is basically where two amounts of the same fluid which contain a different amount of chemicals balance themselves out over time via utilising the movement of molecules.
It is these anaerobic areas which allow for de-nitrifying bacteria to function and therefore convert nitrate into nitrogen gas which will escape the aquarium at the water surface.
So an effective deep sand bed has the ability, because of grain size, depth and various organisms, to permit both nitrifying and de-nitrifying bacteria to co-exist and continuously break down matter all the way through to the conversion of nitrate to nitrogen gas.
When a deep sand bed is combined with live rock in the marine aquarium any solid waste which settles upon the sand is broken down via the deep sand bed and the rest is cycled via the live rock's excellent filtration capabilities - a match made in heaven.
Leaving live rock out of the equation though when a deep sand bed matures the following will happen:
Waste is broken down when it lands upon the surface of the bed either via bacterial processing or via organism consumption.
The upper layer is so oxygen rich that ammonia and nitrite is converted into nitrate.
At the same time the nitrate concentration is being converted into nitrogen gas the nitrate created in the upper layers is 'pulled' down into the lower layers of the sand bed.
When the nitrate reaches the lower levels it is converted into nitrogen gas.
The nitrogen gas which is created rises through the sand and diffuses into the water column before being released into the air at the water surface.
The cycle continues.
Therefore with a deep sand bed we have a never ending biological filtration cycle which is complete all the way through to the conversion of nitrate to nitrogen gas. The majority of other filtration methods stop after the creation of nitrate and other methods need to be introduced into the aquarium to control this remaining part of the cycle, whether this is water changes. . ."