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Re: Re: Peat x Activated charcoal
<fontfamily><param>Geneva</param>Not since the "Hydra Kill" and "The
Ammonia Test" have I done this much work for you guys, but here are the
Activated charcoal is used to remove dissolved gases and organic
compounds. Don't expect the stuff to remove any heavy metals. Not
unless they are complexed with some organic molecule like the humic
acids and tannin from the peat.
It has been my observation over the years that peat has never been
given its rightful due as a water treatment for our fish. People point
out the "dirt" or "mud" on the bottom of my tanks over the years and I
usually explain that it is there left over from feeding white or
grindal worms. I don't pay much attention to the mullum on the bottom
until it is changing time and then I take off most of it unless there
are fry in the tank and I can't get it out with out a few fish. I do
the very best I can to empty and fill each of my tanks every week. I do
not and have never had a RO unit, don't collect rain water or perform
Activated charcoal is a trapping material. It is used to trap chlorine
and other gases within the carbon structure. Most of these gases
eventually react with water and don't pass through. Not all of them
though and leaching from the charcoal will happen if the charcoal is
not thick enough or the flow is too high.
Activated charcoal is an excellent chlorine remover. There are no
chemicals added nor exchanged. Most R/O units need chlorine removed
before the R/O filter and come with a charcoal canister as a
If you have a good activated charcoal bed after the peat, the water
should come through water white not peat colored. That probably removes
any affect of the peat.
Well, that is what I said remembering this experiment I did back in
Texas with the water I had at TCU. Of course that water is very high
sodium chloride and that may have masked some of the results. So, I
have gone through the experiment with St Louis water.
Activated filter carbon from Aquarium Pharmaceuticals, Inc. Purchased
from a local PetSmart and the peat used for the study was purchased
last spring at a local hardware store spring planting sale. I got a
bail of it for $12.00. I brake off a clump of it and place it in a 20
cup cook pot of boiling water and let it fall apart and sink over a few
days. I usually wash the fines out by running water through a handful
in a fish net until the water runs free of most of the fines. I squeeze
it dry and store it in fish bags or under water in the same pot I use
to boil it in. Just keep it covered with water and bring out a
hand-full when ever needed for spawning SA's or the worm box needs
replenishing.(or this test). So a hand full in a fish net, a good rinse
under the faucet and off to my lab at the Ink Co.
I decided on a liter of water and 4 inches of peat in a 1/2 in dia.
glass column. I added the peat to a liter beaker and added tap water to
the liter mark(about a quart). I poured the slurry of peat and water
into the glass column with a wad of cotton on the bottom to stop the
peat. I collected the liter of water after the entire amount of peat
had been washed into the column. The water appeared clear enough that
farther filtration was not necessary. If I had been doing this by SOP
it should be filtered to 0.45 micron before determining the dissolved
solids by evaporation (I am going to have to be paid for this if I do
At the tap, the pH was measured to be 9.43 a little low for these
parts I see it as high as 10.5 and 11.2. As the weather here cools the
water dept. doesn't have to keep the pH quite as high to keep the
chlorine stable and not near as much chlorine is needed because it
reacts with water more slowly at lower temps. After the water had
passed through the peat filter, the pH measured 5.35. this is not
surprising either. If one measures the water in the pot I boil the peat
in, the pH may be as low as 2.5 or so, and there is a smell of H2S. Of
course this was rinsed before I began the test so the amount of H2S
would be minimal . But, definitely, the peat lowered the pH.
And now the hard part, cleaning the charcoal. WHAT A MESS!! Those of
you who use this stuff must really have to work to be sure that the
fines don't get into the tank water with the fish. Talk about nuance
dust! Well, after washing a couple of tablespoon full of this stuff in
tap water in a fine strainer for 30 min., I was finely able to stop the
fines. Stop them until I spooned the chunks into the column that is.
The mechanical bumping and moving the chunks around just stirs up more
dust in the water. I finely settled with extra cotton plugs in the
bottom of the column to filter out the carbon.
I measured the pH after the first pass through the carbon bed, pH
=7.45. After the fifth and 8th still the same 7.5.
To clear the color of the peat from the water, I had to slow the flow
down to about 10 ml /min. and pass through the column 20 times. You
guys ran out of money about that time also. This reduced the color an
order of magnitude and although there was still some yellow, I felt the
process had gone far enough to illustrate the point and the pH was
still 7.5. I do not have a color measurement. I will leave that up to
the next study, but it was only a very faint yellow.
And the final part of the test, the solids and the hardness titration:
Results from the evaporation of one sample each the dissolved solids of
the raw tap water sample: 278 ppm,
The Hanna dissolved solids meter reads 33, same as my home tap water.
The pH: 9.5.
The titration of total hardness: 10 dH translated 10 X 17.9 = 179 ppm
After the peat filter:
The evaporation dissolved solids less than 100 ppm. (See Note 1.
The Hanna dissolved solids meter reads 24.
The pH: 5.05
Titration of the peat filtered sample gave a total hardness of 4 dH or
71.6 ppm, about half of the original tap water.
250 ml(about 2 cups) of this peat treated water was poured through the
washed charcoal in an effort to remove the color of the peat treatment,
The flow rate was adjusted to 10 ml/min. through the bed. The sample
was poured through the bed 20 times at this rate. After 20 cycles
through the charcoal bed, the water was only faint yellow
Evaporation Dissolved solids: over 200 ppm (Yes, back up, and near what
I started with in the tap water.)
The Hanna dissolved solids meter reads 31.
The pH: 7.5.
The titration of total hardness 6.7 dH translated 6.5 X 17.9 = 116 ppm
(At this level of measurement, the organics get in the way. Heating to
the normal 110 C for constant weight chars the resulting solids. This
interferes with this portion of the test. However, the test results
indicates at least a reduction of dissolved solids to 50% of the
original tap water. )
(one dH translates to 17.9 ppm CaCO3 )