How Freshwater Deep Sand Beds Work

[kj5kb]

Plan, Comment and question...

Interesting thread...

My Plan:
-75G open top tank with ~3" DSB.
-Divided into 3 areas for fry, shrimp, etc.
-Planted with anubias, java fern, crypts, swords, najas grass, mangroves(floating and planted).
-Lighted with 2 T8 32W daylight tubes (maybe 4 if I REALLY need it)
-Filtered with 2 large sponge filters...~ 6" dia x 5" high.
-Stocking: caridina and neo-caridina shrimp, red claw macro shrimp, various misc fry/small fish.
-MTS in sand bed, maybe blackworms too.

Comment: I have found Red Cherry shrimp can do a great job on BBA. I too have used excel, but RCS work better and cheaper, just takes awhile.

Question:
How about inexpensive sand?
My thoughts...from what I see available here in NE Ohio:
Play sand-nice, clean, but compacts too easily IMHO
Pool filter sand-nice, clean, loose but it can form anaerobic areas...found some in a 1.5" bed while emptying a tank.
"General/All purpose" sand (used for concrete )-quite dusty, needs a lot of rinsing. looks more natural to me than either play or pool sand.
Small gravel-I have ~ 100 lbs of small gravel...1/4" and smaller, left from screening out the 1/4" and bigger stuff for an RUGF tank.

Maybe a mix of all the above?

 

[DeeDeeK]

Interesting thread...

My Plan:
-75G open top tank with ~3" DSB.
-Divided into 3 areas for fry, shrimp, etc.
-Planted with anubias, java fern, crypts, swords, najas grass, mangroves(floating and planted).
-Lighted with 2 T8 32W daylight tubes (maybe 4 if I REALLY need it)
-Filtered with 2 large sponge filters...~ 6" dia x 5" high.
-Stocking: caridina and neo-caridina shrimp, red claw macro shrimp, various misc fry/small fish.
-MTS in sand bed, maybe blackworms too.

Comment: I have found Red Cherry shrimp can do a great job on BBA. I too have used excel, but RCS work better and cheaper, just takes awhile.

Question:
How about inexpensive sand?
My thoughts...from what I see available here in NE Ohio:
Play sand-nice, clean, but compacts too easily IMHO
Pool filter sand-nice, clean, loose but it can form anaerobic areas...found some in a 1.5" bed while emptying a tank.
"General/All purpose" sand (used for concrete )-quite dusty, needs a lot of rinsing. looks more natural to me than either play or pool sand.
Small gravel-I have ~ 100 lbs of small gravel...1/4" and smaller, left from screening out the 1/4" and bigger stuff for an RUGF tank.

Maybe a mix of all the above?

Inexpensive sand is fine, but why not look for a looser, inexpensive sand? Horse racetrack sand is good, I understand; go by a racetrack and ask where to get it. I know there's places only. If you don't have any corys or belly-crawlers, why not take a look at feed stores for chicken grit (crushed granite for cheap)(don't get the kind with oyster shells in it). Or check local garden centers. I believe concrete sand might be good enough to be worth washing. Look for gravel and sand companies, which may carry a greater variety of sands and gravel, and see if they have a nice coarse smooth grained sand.

As for pool-filter sand forming anaerobic areas, that would be a good thing if the sand were kept open and loose. Anaerobic areas are where nitrate is metabolized into N2, and N20 by using it as an oxidant in place of O2. It's harmless. Anoxic regions, which are absolutely devoid of oxygen, are where H2S and other nasties really off. And again, a nice loose, open sand with plants and critters will take get oxygen deep enough for aerobic bacteria to take care of it before it reaches the water column. Gases come out of my tank's anoxic zone and bubble harmlessly to the surface several times daily.

 

[DeeDeeK]

Check it out. There is an enormous anaerobic pocket under about 3/4 to 1 inch of aerobic sand! It's harmless, nothing gets out of it except the occasional bubbles, which don't stink of hydrogen sulfide. Notice size of the grains; there is a cellphone in the lower right hand corner to compare for scale.

 

[kj5kb]

Hard to tell from the pic but your sand looks in-between play and pool sand. Nice looking too...I see why you chose it. I'm just too cheap to fill a 75G with it.

Re: pool filter sand: I meant to say "despite it being loose, it can form anaerobic pockets" tho what I saw might have been an anoxic pocket...very black and stinky. That tank had NO MTS in it. same tank and amount/type of sand with MTS had no nasty spots in it. Interesting comparison.

Pool filter sand is very loose IMHO. I think it will work fine.
I've been encouraged by a 'real' aquarist to try a DSB with play sand, but I think the play sand we get around here just compacts too much.

I'm thinking pool filter sand with a bag of all purpose (concrete) sand mixed in for appearance. Pool sand is really bland looking...but so is play sand. I already have a "starter culture" of MTS infested pool filter sand from a 20 long that will be replaced by the 75.

 

[DeeDeeK]

Hard to tell from the pic but your sand looks in-between play and pool sand. Nice looking too...I see why you chose it. I'm just too cheap to fill a 75G with it.

Re: pool filter sand: I meant to say "despite it being loose, it can form anaerobic pockets" tho what I saw might have been an anoxic pocket...very black and stinky. That tank had NO MTS in it. same tank and amount/type of sand with MTS had no nasty spots in it. Interesting comparison.

Pool filter sand is very loose IMHO. I think it will work fine.
I've been encouraged by a 'real' aquarist to try a DSB with play sand, but I think the play sand we get around here just compacts too much.

I'm thinking pool filter sand with a bag of all purpose (concrete) sand mixed in for appearance. Pool sand is really bland looking...but so is play sand. I already have a "starter culture" of MTS infested pool filter sand from a 20 long that will be replaced by the 75.

Very cool! Maybe my LFS is selling me pool filter sand? Anyhow I've got limited experience except with fine silica sand which is NO GOOD!

Oh, another source of sand-like material is called "grog," which is crushed firebrick and available in fifty pound sacks for cheap, is porous and textured, and the "fine" grade is quite sand like. Anyone curious should find the nearest ceramic supply company and check it out. I'd like to try using it. Probably no good for cories and loaches.

Ceramic suppliers also sell various grades of silica sand, good quality, much cheaper than other sources I think.

 

[DeeDeeK]

I've been thinking about the no-vacuuming thing. I still like the idea but I think maybe stronger mechanical filtering would be a good idea in some cases, with especially poopy fish or high high bioloads. My own tank has had an episode with hazy water I am thinking now was just because of an excess of dissolved organic matter and bacteria, what you usually get from overfeeding.

In my case, I think I released a bunch of mulm and products of its decay into the water column when I uprooted some dead root systems by accident. My bioload is a bit too high and even a little extra crud tilts the balance.

A more powerful filter would suck up more mulm and while it would slow the processes of decay in the the sand bed, I think that would be ok.

Here's a link to info on live sand in saltwater, with links to other related topics like biological filtration. http://saltaquarium.about.com/cs/livesandsetup/a/aa070198.htm

Autotrophic bacteria such as Thiobacillus denitrificans and Paracoccus pantotrophus can function aerobically, or anaerobically using nitrate as a source of oxygen are examples of especially handy bugs for the biofilter as they denitrify NO3 AND oxidize H2S, and Thiobacillus novellus, which is strictly aerobic, is hand as an H2S oxidizer too. There are many other similar handy microbes which take up residence in these environments, and they aren't from especially rare or exotic genera (plural of genus). Some of the bacteria also consume fatty acids and other organic compounds which come from anaerobic decay.

Oh, here's a pic of some blackworms infiltrating the anaerobic zone, which I don't think I've illustrated before. It's hard to find worms visible through the glass in both zones - but at least they sit still for their portraits. Further down it might be anoxic, but I believe the worms help keep the anaerobic region from reaching too near the surface and keep the aerobic region better oxygenated and deeper reaching, thus supporting the functions of bacteria in the biological filter.

 

[DeeDeeK]

Re: pool filter sand: I meant to say "despite it being loose, it can form anaerobic pockets" tho what I saw might have been an anoxic pocket...very black and stinky. That tank had NO MTS in it. same tank and amount/type of sand with MTS had no nasty spots in it. Interesting comparison.

I've finally seen an MTS dig down to the border of the anaerobic zone, about an inch down! I'd begun to doubt their burrowing. I guess now that they'll go as deep as the borders of the anaerobic regions, which may be pretty deep, and no deeper.

Though they may not plow through anoxic zones and aerobic zones, I think they open up the aerobic zone expand it sufficiently that O2 diffuse downwards enough to prevent most true anoxic zones from forming and the anaerobic bacteria in the anaerobic zone will oxidize what H2S that does manage to form.

 

[Anoxia]

I am cycling my 29 gallon right now with about 4.5 inches of substrate (gravel, topsoil mixed with clay, and sand, roughly in that order), I hope to be able to pull off the full freshwater deep sand bed filtration eventually.

I wish I had waited for it to cycle first, then added plants, then inverts, then fish, but I had some favorite fish from before when it was only gravel, and I didn't want to sell them. So, they are riding out the cycle, and I am doing water changes like a maniac trying to make it easier on them.

It's been four days, and the plants are having a hard time, but I haven't lost any fish. I wish I had been smarter and kept the dirty biomedia from my old filter, but oh well. I am making do with Seachem "Stability" bacteria in a bottle. I can't wait to add snails and worms. I actually had the idea to use blackworms before even seeing this thread, and I was so thrilled to see the worms work!

I got a lot of information from this webpage: http://www.ronshimek.com/deep_sand_beds.html

I am thinking about getting some freshwater plankton and inverts from here: http://www.aquaculturestore.com/

and I am interested in the possibilities of this: http://www.arizonafairyshrimp.com/

 

[DeeDeeK]

I am cycling my 29 gallon right now with about 4.5 inches of substrate (gravel, topsoil mixed with clay, and sand, roughly in that order), I hope to be able to pull off the full freshwater deep sand bed filtration eventually.

I wish I had waited for it to cycle first, then added plants, then inverts, then fish, but I had some favorite fish from before when it was only gravel, and I didn't want to sell them. So, they are riding out the cycle, and I am doing water changes like a maniac trying to make it easier on them.

It's been four days, and the plants are having a hard time, but I haven't lost any fish. I wish I had been smarter and kept the dirty biomedia from my old filter, but oh well. I am making do with Seachem "Stability" bacteria in a bottle. I can't wait to add snails and worms. I actually had the idea to use blackworms before even seeing this thread, and I was so thrilled to see the worms work!

I got a lot of information from this webpage: http://www.ronshimek.com/deep_sand_beds.html

I am thinking about getting some freshwater plankton and inverts from here: http://www.aquaculturestore.com/

and I am interested in the possibilities of this: http://www.arizonafairyshrimp.com/

What a cool DSB site and I think I'd like to order some plankton and amphipods from the aquaculturestore.com place.

Your sand bed setup is very interesting!!!!

 

[Anoxia]

Once my tank is healthy, I will probably get some of those fairy shrimp, they are like brine shrimp for fresh water.

In Ron Shimek's webpage, he encourages very small grain size for DSB, and I read someone else (crud, I wish I remembered who and where) saying that a freshwater DSB would require much smaller grain size than salt water does. That made sense to me, just because I have waded into lakes and rivers, and the bottoms are often muddy. So I used clay. If I had seen the success you are having with only sand before I set up with clay, I probably would have left the clay out. If this clay doesn't work, I will change to sand only, like you are doing.