Deep Sand Bed

[axiekeeper]

Deep sand beds.

I use them, others have concern that they are dangerous, I want to post some information relating to this subject including the reasons I use a deep substrate.

how it works Deep Sand Beds

super long read with lots of firsthand experience Deep Sand Beds for Freshwater tanks

walstad tank related
How Freshwater Deep Sand Beds Work [Archive] - Aquaria Central

and a post containing a couple scientific studies and more links.


The Planted Tank Forum - View Single Post - Quick question about soil

 

[axiekeeper]

I use deep sand beds in my tanks, I have a 120 gallon that has had deep sand in it for more then a year (then I moved and started it over) my axolotl tank ( axolotl habitat ) also has a deep substrate, along with two of my 10 gallon tank.

I believe that lakes also use deep sand beds (but i'm just being a smart aleck on that one )
Ill work on posting more information that is really pertinent from these threads into this thread so that everyone will not have to dig so deep to find the goodies.


If anybody else has got anything related to this subject please post up, but lets not fill this with unsubstantiated claims, back it up with some facts and experience please.

 

[Wildebeestking]

I'd like to see some pictures of it! I've never heard of this method before.

 

[axiekeeper]

(wetwebmedia)
What is a deep sand bed?
A deep sand bed is a sand substrate coupled with bacteria and multicellular organisms working together as a powerful biological filter. Originally developed in the saltwater aquarium hobby, deep sand beds (DSBs) extended the biological filter from converting ammonia and ammonium to nitrate, to eliminating nitrate by denitrification - using the oxygen in nitrate, releasing harmless nitrogen or nitrous oxide. This was desirable because of saltwater organisms’ great sensitivity to nitrate. In freshwater, nitrates are much less toxic, requiring infrequent water changes to control levels, but the freshwater DSB as described in this article does more than eliminate nitrate.

How does the Freshwater DSB work? What does it do?
Primarily, freshwater DSBs are biological filters, eliminating ammonia, nitrite, nitrate, hydrogen sulfide, byproducts of decay, and solid waste (mulm). Secondarily they are good planting mediums because decaying organic matter disintegrates and sifts into the sand, releasing carbon dioxide and minerals which boost plant health and growth.(wetwebmedia)

that first link Deep Sand Beds is a must read, the exert above was taken from it.
one of the cool things is that it is recommended to use california blackworms in the sand to eat the mulm and diffuse it in the sand, of course the axies will also eat them but that just means they need to be replaced.

Ive got a question though, how large in mm can the grains of sand be in an axolotl tank?? this would be for 6 inch and plus axies only. (anything smaller Im keeping in bare bottom till they get bigger)

 

[axiekeeper]

here is my axie tank. that is a 2x4 for reference, the bottom of tank is less then 1/2 inch from bottom of 2x4 so my sand is just over 3 inches deep, ive got to add some more sand to bring it all up to 3 inches min. around food dish, and 3.5-4 inches everywhere else. about 2 inches or less of dirt substrate with gravel and sand mixed in with a "soil mix" i made.

and my gold axie (with cool white spots, can I call him/her a white and gold?)

 

[Olivia97]

This is quite interesting considering the worries of anerobic pockets. Have you used this method for a long time especially with the vacuuming we do to keep our tanks clean?

 

[jasper408]

I would like to make a walstad tank, replacing the gravel with an inch or two of sand at the top. I was worried about anaerobic pockets as well. I am curious though, what is different about this method that eliminates this problem?

 

[axiekeeper]

read the links posted please.
anaerobic pockets are a beneficial part of the process containing very powerful nitrating bacteria.

the vacuuming is fine, just don't disturb the sand too deeply, it will make the sand bed take longer to establish but not an issue. you can also not vacuum the sand with this setup. I do prefer vacuuming all but the actual axie waste (dissipates quickly) I just vacuum the plant waste and that kinda mess. (plants still establishing themselves)

Ive had mine with a dirt bed since around the 5th of september. capped with sand around the 14th, and added my axie three-four weeks ago. plenty of gas pockets in there and no "noxious gasses" my cichlid tank had deep sand for a year with not an issue, 2.5-3 inches+ in some areas (I moved and need to replace the sand as it has silicates contributing to diatom algae...)
but please don't take my word for it as mine is a really new tank compared to ones listed in the threads I posted. The science is solid and the myths need to be dispelled, :happy:

This deep sand bed system is the same as a walstad as far as the anaerobic actions (the association is in the links) a deep bed of dirt will create the same pockets only more so then plain sand will. Deep sand beds have also been used in salt water tanks for decades.

you probably shouldn't have deep sand beds without knowing a little about how they work, (though that is exactly how my cichlid tank was) but the first link will give you all you need to know on that aspect. Do not disturb the deep part of the substrate bed, the first half inch to inch is still completely aerobic and will not be harmed by the disturbance axolotls love to cause, as well as my cichlids.

Seems to me that live root feeding plants are a benefit to this system, and some cali. black worms would be nice as well as other little critters that are recommended in the threads. This is one of the actions that is present in Walstad tanks, just explained. So if you have a walstad setup you are already running a deep substrate bed, just with dirt and sand on top like my axie tank has.

 

[dvsgal]

I saw this method yesterday at a local petshop in abbotsford, not one tank in there has gravel.
The setups look amazing, and you can tell the fish really love the environment.
However it takes approx 3 months to get it all 100% fish safe.

 

[axiekeeper]

Could you post some pics of the fish store tanks?
did the store say why it takes three months?
Thanks for sharing

 

[jasper408]

read the links posted please.
anaerobic pockets are a beneficial part of the process containing very powerful nitrating bacteria.

the vacuuming is fine, just don't disturb the sand too deeply, it will make the sand bed take longer to establish but not an issue. you can also not vacuum the sand with this setup. I do prefer vacuuming all but the actual axie waste (dissipates quickly) I just vacuum the plant waste and that kinda mess. (plants still establishing themselves)

Ive had mine with a dirt bed since around the 5th of september. capped with sand around the 14th, and added my axie three-four weeks ago. plenty of gas pockets in there and no "noxious gasses" my cichlid tank had deep sand for a year with not an issue, 2.5-3 inches+ in some areas (I moved and need to replace the sand as it has silicates contributing to diatom algae...)
but please don't take my word for it as mine is a really new tank compared to ones listed in the threads I posted. The science is solid and the myths need to be dispelled, :happy:

This deep sand bed system is the same as a walstad as far as the anaerobic actions (the association is in the links) a deep bed of dirt will create the same pockets only more so then plain sand will. Deep sand beds have also been used in salt water tanks for decades.

you probably shouldn't have deep sand beds without knowing a little about how they work, (though that is exactly how my cichlid tank was) but the first link will give you all you need to know on that aspect. Do not disturb the deep part of the substrate bed, the first half inch to inch is still completely aerobic and will not be harmed by the disturbance axolotls love to cause, as well as my cichlids.

Seems to me that live root feeding plants are a benefit to this system, and some cali. black worms would be nice as well as other little critters that are recommended in the threads. This is one of the actions that is present in Walstad tanks, just explained. So if you have a walstad setup you are already running a deep substrate bed, just with dirt and sand on top like my axie tank has.

I did read the links, and my question still stands relatively unanswered. The anaerobic bacteria in this case consume nitrates, which is also readily consumed by plants. Isn't that counter-intuitive, especially if anaerobic bacteria, when at a loss of nitrates, start producing sulfurous gas? In theory, a walstad tank would create more problems, especially since as a walstad tank matures, the density of plants increases, whereas the bio-load will not be changing. So, my question was, what eliminates this problem?

 

[dvsgal]

Could you post some pics of the fish store tanks?
did the store say why it takes three months?
Thanks for sharing

I will take some photos of the tanks when im in that area nextweek.

It took approx 3 months as one week the water readings will be fine and the next week the readings are ridiculously all over the place because of the soil and the tanks are heavily planted.

But looking at the display tanks id say its all worth the hassle in the end.

 

[axiekeeper]

I did read the links, and my question still stands relatively unanswered. The anaerobic bacteria in this case consume nitrates, which is also readily consumed by plants. Isn't that counter-intuitive, especially if anaerobic bacteria, when at a loss of nitrates, start producing sulfurous gas? In theory, a walstad tank would create more problems, especially since as a walstad tank matures, the density of plants increases, whereas the bio-load will not be changing. So, my question was, what eliminates this problem?

this same system is what is present in a walstad tank. The aquatic plants do not remove nitrates from the system, they convert them into more plant growth, when leaves, stems or roots die they feed the system, and the underwater variety is really not that effecient at it, definetly not enough to keep up with a well fed group of axies!
You will also not get more anaerobic bacteria then what your system has in nutrients for the bacteria, unless you happen to make a drastic reduction in your bioload after it has been well established for a long period. Ie going from a grossly overstock condition down to a single axie. The noxiuos gasses are a result of the dieoff of bacteria in mass amounts, same thing can happen with any filter in a power outage if the water stops flowing the bacteria dies and you just flip it back on it will essentially poison your tank.
What this system can do is survive power outages, in fact it doesnt care at all.

So the benefit of this system is that once established it is truelly stable and balanced system and more natural of an enviroment, as well as fewer water changes and healthier plants. The salt guys have this in their tanks and hardly do water changes whatsoever ecause their biological bacteria system is complete do to nitrate reducing anaerobic bacteria, something still missing in many freshwater setups.

Im gonna be redoing the substrate in my 6foot cichlid tank and putting in 3.5 inches of sand that contains nice little stones (just cause it looks good) my fish will not tolerate plants so it will not have any. This system will still be very benefitial without plants and simpler as well.

 

[Chelsea smith]

I also had a deep sand bed that lasted for over a year. Fish and plants both thrived, but I wasnt just using sand and soil, I kept mesh between all that, and clay balls I used to completely cover bottom layer. Had a sub pump that was housed on bottom level so it pulled water from the clay balls, which pulled from soil, and so on, pretty sure that kept my tank from ever crashing. It was awesome...