Fresh water Deep Sand Bed

[Mr.Catfish]

Here's a good read about deep sand beds http://www.farmertodd.com/pdfs/native_fish_tank.pdf

 

[countryboy]

Put very simply, even without plants, snails and worms, think of the deep sand bed as a huge bio-filter.
Many have come to believe that beneficial bacteria only lives in the filter. In fact, in the established aquarium, there is far more biology in the substrate. Deep sand just extends the platform to also accommodate anaerobic bacteria in it's deeper layers. The key is to NOT disturb the sand or disturb as little as possible.

Deep sand, like any other bio-filter, does not eliminate a need for some mechanical filtration, water circulation, and water changes. HOWEVER, leveraging [more] biology allows us to have a healthier tank with less filtration and lower volume (or less frequent) water changes.

Taking it to the next level, deep sand, living plants, MTS/worms, etc. leads us to a nearly self sustaining biotope. Consider...

Aquabella.com
Aquaripure.com

They tell us that with only modest mechanical filtration and the right bio-filtration, we can dramatically limit water changes while maintaining healthy tanks with crystal clear water.
Oh you can run canisters + hobs and change out 50% of the water weekly - that's one way....but just maybe it's not the only way and may not be the best way.

I know that the substrate and rock of what ever sort carry bb. I stated above that I thought that the dsb had to be undisturbed. I have seen marine dbs's that need no other filtration other than wc.
Dsb's in freshwater....if it were viable more ppl would use them.

 

[mesto]

Well, I set up my next aquarium differently not because I don't like my sand, but because I am trying to figure out what's from plants and what's happening in the sand itself. And again I think some of this comes down to a personal preference for aquarium style.

What exactly do you mean by "viable"? From what I read marine DSBs still want like 10-20x water flow etc, and many people also use protein skimmers or additional filters with them, so I don't think those are always as simple as only needing sand either. I also know bioload in a typical marine aquarium has to be lower than in freshwater. I honestly think you could set up a freshwater DSB with a powerhead and only have to do WC as long as it was lightly enough stocked and had the right mix of species.

You said something interesting about not buying denitrification in freshwater (at least I think that's what you were getting at) - why is that?

 

[SubRosa]

Denitrification absolutely works in FW. The reason that I don't consider a dsb to be a viable option in most FW set ups is because there are potential drawbacks to a dsb, as have been previously mentioned, and getting rid of nitrates and other things that accumulate is so easy with water changes as compared to SW.

 

[countryboy]

Okay..I have been reading about dsb's in fresh water aquarium for about 3 hrs. I give. They do work. Most of the ppl do however have additional filtration. I know septic systems work but I don't want one in my dinning room.

 

[mesto]

Yup, makes sense. The idea appealed to me, but to each his own for sure. Like I said, I know mine has not been up for long, nor have I been doing this for long, so we shall see how it goes.

 

[AbbeysDad]

Put very simply, even without plants, snails and worms, think of the deep sand bed as a huge bio-filter.
Many have come to believe that beneficial bacteria only lives in the filter. In fact, in the established aquarium, there is far more biology in the substrate. Deep sand just extends the platform to also accommodate anaerobic bacteria in it's deeper layers. The key is to NOT disturb the sand or disturb as little as possible.

Deep sand, like any other bio-filter, does not eliminate a need for some mechanical filtration, water circulation, and water changes. HOWEVER, leveraging [more] biology allows us to have a healthier tank with less filtration and lower volume (or less frequent) water changes.

Taking it to the next level, deep sand, living plants, MTS/worms, etc. leads us to a nearly self sustaining biotope. Consider...

Aquabella.com
Aquaripure.com

They tell us that with only modest mechanical filtration and the right bio-filtration, we can dramatically limit water changes while maintaining healthy tanks with crystal clear water.
Oh you can run canisters + hobs and change out 50% of the water weekly - that's one way....but just maybe it's not the only way and may not be the best way.

I know that the substrate and rock of what ever sort carry bb. I stated above that I thought that the dsb had to be undisturbed. I have seen marine dbs's that need no other filtration other than wc.
Dsb's in freshwater....if it were viable more ppl would use them.

Simple skepticism and 'fish lore' prevents advancements like these (even when everyone accepts live rock and live sand in SW). Consider that many still use under gravel filters in the face of a raging 30 year debate!

Not disturbing the sand bed allows organisms the ability to develop at the appropriate levels and work in concert with each other much like it does in nature.
And think of decaying mulm, like mulch and compost in organic gardening instead of removing debris and adding chemical fertilizer. This material feeds the beneficial bacteria in the substrate which feeds any rooted plants.

It is true that with good bio-filtration like a deep sand bed (or other) and a moderate or heavily planted tank with a light stock load, very little filtration is required - but there needs to be water circulation which minor mechanical filtration would provide. The tank would still benefit from routine water changes, but it's logical that these water changes might be less frequent than weekly and/or less volume than might otherwise be required.

Just another way to manage our aquatic environments.

 

[countryboy]

One last point and I have to admit it bugs me. You don't need a filter to circulate water. A wavemaker will do.
Sorry....
Last year I wanted to start a SW tank. Not quite a FOWLR but with some coral. I didn't want to buy all new equipment for filtering, reactors etc. so I looked into DBS with live rock. Allot of people on Reef Central said it could not be done. One guy said yes it could. So I decided to not persue it. A few months latter I was at my LFS. He has a marine set up without any external filtering. Has 2 circulating pumps. Does water changes to help reduce nitrates. I had'nt noticed the tank there before. He said it's been up and running for 5 yrs.
I always thought that allot of things that are done in salt can't be done in freshwater. And so the skeptism.

 

[AbbeysDad]

One last point and I have to admit it bugs me. You don't need a filter to circulate water. A wavemaker will do.
Sorry....
Last year I wanted to start a SW tank. Not quite a FOWLR but with some coral. I didn't want to buy all new equipment for filtering, reactors etc. so I looked into DBS with live rock. Allot of people on Reef Central said it could not be done. One guy said yes it could. So I decided to not persue it. A few months latter I was at my LFS. He has a marine set up without any external filtering. Has 2 circulating pumps. Does water changes to help reduce nitrates. I had'nt noticed the tank there before. He said it's been up and running for 5 yrs.
I always thought that allot of things that are done in salt can't be done in freshwater. And so the skeptism.

First of all, reef tanks have to have alternating pumps to simulate the waves or surf. It's the only way corals and anemone's get to eat.
Also, in any tank, given sufficient water change frequency and volume, no extra filtration (beyond sand bed and plants) may be required. It's all about balance and creating a 'pure enough' water environment for the stock.
We use filters for a better display tank and so we can just do modest weekly water changes.
So we can have large volume and/or frequent water changes, or we can better filter/purify the water in which case the volume and frequency of water changes can be less - it's really that simple.

Now I have also read articles and seen youtubes where FW tanks use sumps and refugiums. SW and FW are not night and day (although protein skimmers don't work in FW )

Now a big reason for weekly water changes is to keep nitrates in check. Less of an issue in moderate to heavily planted tanks. Some will argue that we need to water changes to also remove pheromones, urine, etc., but they are just more organic compounds that can be processed or filtered. But if we leverage biology (e.g. deep sand or denitrate filter) to remove nitrates, then water changes (frequency and/or volume) can be safely reduced.
I'm almost tempted to give Aquabella a shot. (Note that I have no affiliation whatsoever with that company).

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