Deep Sand Bed Experiences
looking for peoples experiences concerning the Deep Sand Bed.
problems i've heard presented are nutrient buildup and fears of Hydrogen Sulfide.
i'm aware of those concerns.
internet and forum searches for info and possible problems have reached a dead end culminating in the above mentioned concerns about why they are not a good thing to use in an aquarium (any aquarium - freshwater and saltwater)
waiting for the new year when finances are again available (welcome to Christmas expenses)
asking ahead of time so i can get an idea what problems to expect and what can be done to resolve those issues.
curiosities i've got
-sand grain size ?
-sand depth ?
-how long it's been running (how long before it failed) ?
-any spikes in ammonia/nitrate/nitrite ?
-(for those that failed) guesses, observations, symptoms, smells going on when it failed, even those that don't seem relevant ?
-any critters in the substrate (if present/used) ?
everything i've encountered about why a deep sand bed should not be done are given the same argument: concerns about Hydrogen Sulfide.
i'm aware of how toxic this gas is in the aquarium. it's one concern. a concern that, as much as i can find, can be neutralized. a concern that has been brought up by people who do not talk about what they were using in their substrate (above questions)
I've done quite a bit of reading about sand substrates, deep and not. Some of the last were on a few posts here but I cannot come up with any quick links for you. I was reading one that mentioned 3" and deeper and it not being the concern that everyone thought it was as long as you don't stir it up. The problem posed was that in stirring the sand to release supposed gas pockets, the mulm gets mixed into the anaerobic zone and causes more trouble in addition to messing with the established various bacteria. Things like trumpet snails will naturally stir up the top 1", but not much more, and the rest looks after itself.
Personally I am aiming for a 1" sand substrate up front perhaps going as deep as 3" at the rear but heavily (as much as I can get away with) planting substrate rooted plants back there. There are some good plants that really root up and that helps in keeping the substrate noxiousness down.
All this is based on no experience, just research so far, so take it as incentive to keep looking into it. If I run across my sources again, I'll post some here.
gas pockets could be H2S, (very toxic), could also be CO2 (beneficial), could also be Methane (toxic).
yet findings from people in nature where there was the toxic hydrogen sulfide, it comes up in bubbles when walking on the sand in the water, it stinks, and there's plenty of fish, and other critters living in the water.
hydrogen sulfide is also characterized (if bubbles don't form) by a layer of black sand/mud, sure it's an obvious sign of what's going on. as a bubble though on it's rush to the surface, i don't think it's going to do any damage to anyone other than our nose unless we keep it in the water column till the whole thing dissolves.
like your findings, it's not a concern.
as for having a sloped substrate, ... i'd guess your snails will try to level it out for you, your plant roots may have something else to say about that fortunatly, then a tug-of-war.
i'm starting to wonder about the whole deep sand bed debate, not doubting it, but doubting those for and against it don't seem to understand a lot of what's going on. or how much is needed.
i've never heard of anyone stress-testing it. what is it capable of handling, from one persons experience i've heard, ... a lot. she had 3x the recommended amount of fish in her tank, and the water was still safe.
so it's changing things and that's not really acknowledged.
it's also resulting in tanks that are having no water changes in years till another problem is faced, no one understands that problem, so it's not being looked at, only used to give up on a resolution.
again it's changing things.
so i've got a guess (formed yesterday) about that problem, listen to other peoples experiences. they either support the guess, or not, regardless anyone who has any test results and numbers help let me know if my guesses were accurate or not.
all i can say, about deep sand beds (outside of my personal interest in their promise), we can either learn or give up on them. i'm choosing to learn. and it sounds like what has been written about them touches the surface but there's a whole new area to consider that their use brings to light. ... or my guess is wrong, but if i don't ask i'll never know :)
The only real number that makes any real simple sense that could be used is 1". That is the prime area where there is gas exchange allowing regular processes to occur that already do occur in the tank. Plenty (or enough) of O2 to promote normal biologicals that we are OK with. It's the deeper part that scares everyone... or some.
If everyone just stuck with 1" of sand, there would be no issues and the tank would be easy to clean. I figure that if most of my tank is 1" and the slope increases to perhaps 3" in back it should be fine. I only want more depth as I think that rooting plants may like it better. Given that the sand is actually heavier than I imagine it to be, I anticipate that I really don't need more than 1" anyway. I don't think that I would really notice the slight slope so aesthetically it makes little difference.
Even my daughter said to me the other day, "I think I should have sand instead of gravel, it would be easier to clean". This while cleaning her Betta bowl. We hadn't talked about sand as the aquarium is mostly a surprise as a family Christmas gift... she sort of knows as I had to figure out if everyone was OK with the idea.
Ron Shimek's Website...Deep Sand Beds
I would not run one myself. If run in a Sump you stand a better chance of it being stable.
1" -1.5" covers the aerobic layer, will deal with your ammonia.
it's deeper layers that deal with de-nitrification. those who are against it propose fears they can't test for without understanding what is going on.
Ron Shimek's page is ... it's a good starting place, but it lacks explanation. also lacks explaining why some of the critters he chose for his substrate are questionable at best. i know i'd steer clear of the critters he decided on.
like anything in the scientific world, the guy who came up with it gets the recognition, but if it can't be repeated by others, he gets recognition for being a nut too.
i don't think there is enough understanding in the deep sand bed, what is being done by those who are picking it up and trying it are playing amateur instead of professional. is it actually a failure, or is it a success if paying attention to key points. if it's a failure, what is going wrong ? is it actually the deep sand bed, or something else.
like here, like other forums i've asked, ... get a lot of people who haven't tried it, and very few people willing to talk about their experiences.
they nay-sayers have a field day with all the hear-say but ... if dozens if not hundreds have tried it, what are their results ?
looking for experiences.
I understand. Good luck, you'll not find many who have done it. And those that have mistakenly done it ruined thier tank and don't much like talking about it.
A few snippets from the article you linked RM...
"...one cubic ft of sediment....the total sand surface area is about 14,828 square feet or just slightly over 1/3 of an acre. A LOT of bacteria can live with that amount of space!"
Now there is an interesting way to look at sand, surface area. In the article he compares the surface area of the sand to larger "cubes", but that could represent gravel, and the difference is in the eight times more range.
"The breakdown of nitrogen compounds to nitrogen gas is done by bacteria growing in the areas of lowered oxygen concentration in the deeper parts of the sediments."
He is referring to 4" depth in a saltwater reef system, although the same principles would apply to freshwater, I couldn't really comment on how this may differ, or even if it does differ.
"Hydrogen sulfide will indeed be formed in the lowermost layers of a deep sand bed. It will NOT migrate up through the sediments to poison a tank. Hydrogen sulfide is an amazingly toxic gas, but that toxicity is exceeded by its pungent rotten-egg odor. The gas will have an exceptionally strong odor, and will seem overwhelming at levels well BELOW toxic amounts. If you can smell this stuff without it literally taking your breath away, it won't be at a harmful concentration. There is no real evidence to indicate that it may reach toxic levels in a deep sand bed."
I wonder if 3" is even deep enough for this to be a remote concern.
"The only real problem with a sand bed is the reduction in diversity as the bed ages. This is caused by extinction and replacement problems because the volume of our beds is simply too small for some species to generate self-sustaining populations."
OK, adding bugs may be necessary. Using the sand from sources that we use will not provide any bugs in the first place so it is technically "dead". i was considering adding some sort of worms (research needed to refresh my memory on which ones) to provide some stirring and processing. Unlike the salt water community, we don't have a lot to go on for sand bottoms as our aqua-vironments are not as seemingly complicated as the reef ones.
There are a few here who use it and recommend it but bad news sells. Who wants to read about a successful sand experiment or tank... other than maybe you and I?
Ron's bugs are for saltwater, whole different bunch. Good luck trying to find live freshwater sand.
hydrogen sulfide does diffuse up, it's also a rather reactive chemical
when reaching the aerobic layers (top inch or so) it will react with the oxygen.
Hydrogen sulfide is produced, slowly, it will diffuse through the sand slowly, it will react and neutralize before entering the water column.
problems and worries are when the substrate is fine enough that hydrogen sulfide is produced faster than what it can diffuse out of the area (very fine substrate indeed) then bubbles are formed.
hydrogen sulfide is also visible as a tell-tale blackness in the substrate.
from another thread on another forum one of the members talked of his experience at whatever lake/river area to see how the layers actually form in nature, and indeed several inches below the surface there was a dark layer (tell-tale H2S signs) and a thriving wetland.
plant roots in the substrate change things, they add oxygen to deeper layers (everything surrounding their roots) Hydrogen sulfide in this situation bearly has to go anywhere before oxygen is present to neutralize the toxin.
every talk, discussion, debate, argument that has involved fears of Hydrogen sulfide point out and emphasize how truely toxic it is, ... if you've got enough in your substrate that has not diffused to aerobic layers and been neutralized, there will be a significant amount there.
so they have a point.
it is there.
now if you want to kill your tank, i hear this would take minutes to do to go from a healthy thriving tank to a bunch of dead fish. ... about 2 min. or so from those who have talked of such an experience.
quicky uproot your plants that have an extensive root system.
this will release all the H2S directly into the water column before it has had a chance to be neutralized, and before you can catch your breath (smells like rotten eggs) you'll have a bunch of dead fish.
if your the kind of person that feels a need to constantly tinker with your plants in your tank, stick to a shallow bed.
if you want a deeper bed to complete the denitrification cycle so your nitrates don't climb out of control, leave your plants to grow on their own, once rooted only remove those that died.
either slowly (gently with jerky motions) slowly pull the plant out of the substrate that has died, or just cut it off and leave the bacterial processes already present in the substrate to break it down for you.
some people cannot leave the substrate and it's plants alone, this is of more importance in your decision to stick with a shallow 1.5" substrate or a deeper 3" or more (preferably 4" or more)
for our tanks not being as complicated as saltwater, ... we've got plants.
now i don't know where deep oceans are getting their oxygen from. so that's a mystery to me.
in aquariums, marine/reef tanks, it's different, that's all i can say.
i haven't looked to find what does the same thing, or why each type of filter is in place. in time i'll be looking into that as well, ... till then i'm going to find as many answers as i can in the freshwater tank, see where their similarities are in the saltwater tank. ... maybe this will answer all my questions. regardless saltwater is providing an inspiration for many of my searches & inquiries as they seem to have spent more time & money on things.
like if your paying $60 for an average fish compared to $5 in freshwater, ... your going to spend that much more on pumps and filters. so those companies are more inspired to build a machine to solve any particular problem in saltwater. they've got more money to spend :) they're willing to spend more money.
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