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Hey guys, am about to set up a 50g planted tank and I think Im going to use fresh clay, river sand and gravel.

My question is, how much clay do I put in the bottom? The tank is about 50 gallons. In fact, how much river sand and gravel do you recommend using? Might as well get all 3 amounts now that Im here.

Thanks alot, appreciate it

ETT.

Hi,
What you are setting up is a recipe for disaster.

I can't figure out why you would use a layer of clay,
cap it with a layer of sand, and then cap that with a
layer of gravel.

When setting up a tank with clay, you should realize that
"we" are not using clay from the back yard so to speak.
Rather "we" are using a layer of Laterite and ancient
clay that is millions of years old. A layer an inch to
an inch and a half, across the entire tank is sufficient.
Then the Laterite is "capped" with a layer of gravel or
sand. The normal depth of the cap layer is from one inch
to two inches thick. The combined depth should be around
3-4 inches thick for a planted tank.
I would recommend against using sand. Sand will
compact, and as the detritus builds up, and the clay
particles settle out, the sand will become packed and
the tiny spaces between the grains clogged.

Note also that when planting this tank you should plant,
the plants, in the cap layer taking care not to disturb
the clay layer. The plants will grow roots into the clay
layer. When uprooting plants to move them or from
energetic fish, clay particles are pulled through the
cap layer and up into the water column where they form
a brown cloudy mess. Only a diatom filter will clean that.

This link will help you calculate the amount of substrate
you will need. You will have to work the calculator twice.
Once for the Laterite, and once for the cap layer.

http://www.plantedtank.net/substratecalculator.html

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Hello Frank, Im glad you intervened in this thread as Red Phantom had told me you have alot of experience with clay and planted tanks.

Let me briefly explain what has happened.

I set up a 20 gallon about 2 months now with this fresh clay which Im not sure if Im employing the correct as I went to a store here and asked for 'arcilla' which roughly translates as clay (the stuff used to make pottery, at least here in Costa Rica) and used that.

Anyway I put that at the bottom, then I put this mix of dirt called 'lombricompost' and a 'bokashi' substrate used for orchids. That followed by a layer of sand and that followed by a layer of gravel. I planted the tank and almost 2 months later, Im not going anywhere. For weeks and no matter how much water I change, the tank has a yellowish slightly reddish tint. The tank looks like Mars in the middle of a monsoon. Some of the plants, the stemmed ones are rotting.

Basically what you are recommending then is to use one or the other, be it sand or gravel but not both? Also, youd rather use gravel and not sand, is this correct? Finally, the clay I should be looking for is 'laterite' exclusively? Is this correct?

Sorry if Im reasking these things but I just want to be 100% sure of what Im doing before I buy a 50 gallon and attempt a planted tank there.

Appreciate the help

Hi,
When I tried it, my tank also started to smell like a
septic tank!

If I were you, I would strip out the tank and clean
it well.

Next, do you have access to a book titled
THE ECOLOGY OF THE PLANTED AQUARIUM by Diana Walstad?
You can read/use either volume one or two.

If you can get your hands on this book, read it before you
restart the 20G tank.
What you are trying to do, you can, but you must do it
carefully. The theory, and practical instructions are in
Diana's book.

The problems with the substrates that you used are that
they are for terrestrial use and not aquatic use. They
are too full of organic waste, and organisms. When
submerged under all that water, they die and putrefy,
ruining the tank and making the water polluted.

As far as the brown color is concerned, that is most likely
the clay particles floating in the water. That comes from
using the wrong methods of introducing the clay and water.
When done correctly, some clay in the water is normal, and
it will take a Diatom Filter, such as this:
http://www.diatomfilter.com/products/diatom_d1_filter.htm
to clean the tank. I have one of these and it will
turn a mud puddle into liquid crystal inside an hour
or two.

"Clay" is a geologic term that is used to describe rock
or mineral fragments that are smaller than a very fine
silt and run around 4 microns or 0.00016 inch or less
in size. Typically these minerals and particles
are fragments of quartz, feldspar, carbonates, and
iron, along with some magnesium, potassium, and
aluminum. Modern clays (less than a few million
years old) have more organic particles than does
the ancient clays.
Laterite is an ancient clay that is mined, cleaned,
and then packaged. "Flourite" is Laterite that is
mined, cleaned, wetted, and then baked. That process
turns it into bricks which are then ground into
aquarium gravel and marketed as "Flourite by SeaChem"
and others.

You can use just about any clay, including the clay found
in Kitty Litter (UNSCENTED - ONLY) as a base for your
substrate, but truthfully, Laterite is the only one really
recommended. A layer of clay about an inch thick is
placed on the glass bottom of the tank followed by a cap
layer of aquarium gravel about two inches thick. When this
was first started, it was used in conjunction with heating
cables that were first placed throughout the bottom of the
tank, on the glass, and then the clay was placed on top of
the cables, followed by the gravel. The cables were
connected to a low voltage, high current source and they
got warm. The warm cables caused the water around them
to heat up and flow upward through the clay (taking the
nutrients and fertilizer with them) through the gravel and
into the tank. As the heated water flowed upward, cooler
tank water was drawn down into the gravel to the wires and
back up. The circulating currents prevent the substrate
from becoming anaerobic and toxic.

Again, the usual way is to put down a layer of clay, and
cap the layer with a thicker layer of aquarium gravel.
When adding water, place a plate on top of the gravel and
trickle the water onto the plate so that it seeps into the
gravel. Once the water level is even with the plate then
you can pour the water onto the plate a LITTLE faster.
Take care the currents don't disturb the gravel.
Have a good filter, and be aware that it will take a few
water changes and the filter to return the tank to crystal
clear water.

When the tank is about half full then carefully plant the
plants in the gravel layer. Don't push them into the clay
layer. The roots will grow into the clay layer and thrive.
When ever pulling a plant up to toss, or to replant
elsewhere, you will bring clay particles up through the
gravel and into the tank itself. This will cause the
water to turn into a brown, cloudy, liquid.

Note that I have deliberately left out "sand" as a
suitable substrate. It simply clogs too easily in this
application. You cannot clean it throughly enough, and
risk sucking the sand and clay into siphon when cleaning.

Find and Read Diana's book, and then tackle the 20G tank.
If you follow her procedures, you will have a true aquatic
garden.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Hey frankie, once again, appreciate it.

This laterite is also used fresh right? I dont have to bake it or put it out in the sun so it hardens, is this correct? Basically grab laterite and spread it evenly about an inch thick at the bottom and on top goes the layer of gravel which should be about 2-3 inches thick?

Yes, that is correct.
You really should read the book first though.
Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--