How Freshwater Deep Sand Beds Work

:OT:
:hitting:
http://edis.ifas.ufl.edu/hs184
Ive seen similar concepts made, and set afloat into ornamental koi ponds, where the plant roots filter the water, keeping it clear.

Quoting another site,
"floating flower gardens and “floating turf islandscapes” that are interesting to look at and serve a useful purpose too: they mimic a “natural peat bog system in which plants and beneficial bacteria absorb excess nutrients that encourage algae growth.” This can be particularly helpful if your pond is cloudy, as it will purify the water so it becomes “become clearer and cleaner.”"


Now I had an epiphany of sorts on this. Now obviously its very hard to do this in an aquarium, but, what of, say, duckweed? Or a personal favorite that I don't have any more of because some one threw some chlorine into my ornamental pond to kill algae :cry:, salvinia.
Now, salvinia is wonderful. Duckweed gives tiny little roots, but also a snack for some fish, while the larger salvinia can give you an EXTENSIVE root system on the top most layer of your aquarium, hanging free in the water instead of below your sand. It provides wonderful emergency control for the water when your substrate layer becomes a tad overloaded. I recommend it to every one but check your state laws on it, as its illegal in a few states do to people dumping it into the wild.
It DOES require you to 'cull the herd', as in optimal conditions it grows like a weed, worse than any other plant I've had.
http://weeds.hotmeal.net/weeds/Giant_Salvinia.jpg
Some of the "roots" are actually some sort of submerged leaf that is incredibly hairy, providing tons of surface area for beneficial bacteria, and trapping small free floating particles. Ive seen water fleas scatter like flocks of birds when you disturb salvinia.

Its almost like sandwiching your water between two sand beds :P
 
I added lemnia minor duckweed to my tank after hearing rainbows and platies eat it, but I guess my rainbows and platies never heard about that. They haven't caught on to the idea of eating it just yet.

I can see why people consider it a pest now, because whenever I have to reach into the water for something, it coats my arm, and it does block the light to the plants below it if I don't keep it thinned down by half regularly. Apparently it is nearly impossible to get rid of, too, but I like it for the water clarifying aspect you mentioned, and I don't think I will try to get rid of it, even though rinsing it off my arm daily is annoying. Every time I scoop out a bunch of it to throw out, I think of it as getting rid of the impurities it has absorbed.

If I had known my fish wouldn't try eating duckweed, I would have gone with salvinia instead, because it sounds like it has a lot of the benefits of duckweed, without being little enough to stick to everything.

Oh, and I found out growing vegetables hydroponically uses 90% less water than in the ground. Just a fun fact. Back to the DSB discussion currently in progress.
 
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I just love this thread!! But I'm soooo confused!! Everyone says they use a different type of sand. So which one is best? Cheapest would be a plus. :) But if I have to pay a little more to keep my critters healthy, so be it.

I really like the idea of no vacuuming!! I currently have the cheap gravel from PetsMart. It was about 2" deep. I've thinned it down alot in the tanks without baby shrimp. If I push the vacuum way down in, I get yucky stinky black crud. And I vacuum alot! Do I overfeed? Yep. After years of rescueing a variety of animals, I don't want anyone to go hungry. But I don't get to do that anymore. So I have aquariums full of critters! LOL And I can garden in the house. I've been in this hobby for less than a year. There's alot to learn!! ;D
 
I just love this thread!! But I'm soooo confused!! Everyone says they use a different type of sand. So which one is best? Cheapest would be a plus. :) But if I have to pay a little more to keep my critters healthy, so be it.

Well, the best substrate is the one that best does what you want! Now, you mention not vacuuming. Perhaps you'd like a sand which allows mulm to settle into it fairly rapidly. I'd think pool filter sand would be the finest grade of sand you should consider. It is meant to allow solid crud in and trap it so it has a very even grain size and doesn't pack down very tightly. The LFS owner got a bunch of sand with a grain size of just under 1mm, which is very big for sand, just short of being fine gravel. It is meshed for a very even grain size so it doesn't pack down much at all and the DSB I made from a layer of it over a layer of pool sand practically eats mulm. It always looks pretty clean but down in it there's lots of decaying mulm that gets kicked up if you disturb it.

To keep it very simple, look for pool filter sand. It'll work for sure. Put down 3 to 4 inches of pool filter sand, cycle the tank, plant it, and go! To cycle the tank, try just feeding it with fish food like there were some actual fish in it. The food will decay and provide the ammonia for the cycle. When the ammonia level is nice and high, stop feeding the tank. The rotting food becomes mulm and works its way into the sand, making it more fertile for the plants to come.

It can really be that simple.
 
Quick questions about black worms and vacuuming

mmm.Added lots of goody blackworms today- finally my order came in, yay!
Ok should I vaccuum and only the surface?
Their tails were sticking out of the substrate, and I don't know if they burrowed down, or gold ram ate them...he was looking quite fat.lol
 
I like a combination of pool filter sand(white) and riversand, it come out as cinnamon whenever you want to change the look from layered :)
(or if you have a chipokae, who is a construction worker!) He is visiting the pyramids at the moment.
My deep sand bed is some gravel, some river sand (70%).
Now layering with pool filter sand, wish I had more river sand right now, that is definately my preference- and it comes with mud already.
Pool filter sand is inert, and has no beneficial properties, so thats why I like to mix them.
 
mmm.Added lots of goody blackworms today- finally my order came in, yay!
Ok should I vaccuum and only the surface?
Their tails were sticking out of the substrate, and I don't know if they burrowed down, or gold ram ate them...he was looking quite fat.lol

Yes, if you must vacuum, just run the vacuum close enough to the surface to suck up what's on it - don't disturb the sand. BUT you should let mulm sit around to decay, disintegrate, and work its way down into the sand. Mulm provides minerals to your plants and releases CO2 as it decays - which is good for plants but also for nitrifying and some denitrifying bacteria, which are autotrophs, organisms able to form nutritional organic substances from simple inorganic substances such as carbon dioxide, using energy from oxidizing NH3/NH4, NO2, or H2S using O2 or in the case of H2S, NO3 OR O2.

The DSB's bacteria will eventually mineralize the mulm, meaning they'll have eaten up virtually all the organic content or released it as dissolved organic compounds (which other bacteria will eat - they prefer pre-dissolved molecules to eat) some of which can actually chelate minerals like iron and make them more available to plants. The volume of material left by the time it reaches the bottom of the DSB is negligible if things are going right.

So you see, a DSB is not just a biofilter for dissolved gasses but also takes care of solids and dissolved organic compounds!

Though there are differences, Diana Walstad's method employs virtually the same principles of the freshwater DSB and I'll plug her book once again because it is so great and is what inspired me to examine the practice of keeping a DSB which is actually fairly common in San Francisco and to write so much about it.

"ECOLOGY OF THE PLANTED AQUARIUM" by Diana Walstad is an absolute must-read!

Oh, yeah, when I re-stock my blackworms (which I had to do a LOT when I a a blue ram and kuhlis), I simply feed so many into the tank that the fish get stuffed and leave the rest alone. Kind of like how military officers send so many men into the line of fire that the enemy runs out of bullets.
 
Ducatigirl - Keep a close eye on your chemical readings if you added fresh sand on top of established sand. My aquarium started a whole new cycle whan I did that. I think it was because the new sand layer smothered the aerobic nitrifying bacteria. I spent almost two weeks doing 3 water changes per day. Not much fun.
 
Ducatigirl - Keep a close eye on your chemical readings if you added fresh sand on top of established sand. My aquarium started a whole new cycle whan I did that. I think it was because the new sand layer smothered the aerobic nitrifying bacteria. I spent almost two weeks doing 3 water changes per day. Not much fun.

Let me second that! I have a second DSB tank currently and it had not quite deep enough of a sand bed so I added more. I even gently stirred to mix some of the lower sand with the new upper sand and I used a turkey baster to suck some more up from below and squirt it on top but I ended up having a small cycle (short with low peak levels) anyhow. I lost 6 out of 16 shrimp and all but one scud. Anoxia's hypothesis re. smothering existent nitrifying bacteria rings true.

I'd suggest scooping up much of the current surface layer of the sand bed, adding the new sand, then spreading the old surface over the new sand. Wow, what an operation! That's how I'd do it if I ever try adding more sand again.
 
Dee- i have read your article and find it quite fascinating! I was wondering where I would be able to get a "starter" of the creatures that live in the freshwater sandbed. i am about to double the depth of my substrate so that it will be deep enough to have a fw sand bed
 
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