Cycling and Bio-Filter in Planted Tank
 

In article . com,
Frank wrote:
the ferts would have the same problem too because the carbon is soaking
up the nutrients? no?
That makes no sense. Who says this?

Makes sence to me - activated carbon removes; ammonia, nitrite,


Nope.


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Cycling and Bio-Filter in Planted Tank
 

Frank wrote:
Altum wrote,

The only thing plants don't remove from your list is solid particulate
waste and much of that settles in the root zone.


Plants do not remove inorganic pollutants such as DOCs (Dissolved
Organic Compounds = uneaten foods and fish waste) from the water
column. As a matter of fact, a 20% weekly water change still leaves
about 30 days of accumulated DOC pollutants in the tank. DOC levels can
be determined by comparing the differences between a chemical hardness
test and the TDS (total dissolved solid) reading from a conductivity
meter. As the DOCs start to accumulate over time, the water starts to
turn yellow and the water quality starts to drop.

Actually, I've never had the water in a planted tank turn yellow the
way it does in a fish-only tank. That's why I thought they removed
DOCs. As a general rule, plants use pretty much every molecule they
can "get their hands on." I don't have access to a conductivity meter
so I'll have to take your word for the measurements.

Cycling and Bio-Filter in Planted Tank
 

Richard Sexton wrote,
Nope.

OK, OK - I got carried away, your right :-( , carbon does not remove
transparent inorganics! ............ Frank

Cycling and Bio-Filter in Planted Tank
 

On Sat, 4 Feb 2006 16:07:48 +0000 (UTC), (Richard
Sexton) wrote:

In article ,
fusQuanto wrote:

That makes no sense. Who says this?


actually its only the melafix that says it, not the ferts. i figured
the ferts would have the same problem too because the carbon is soaking
up the nutrients? no? im not a chemistry nor biology major so perhaps
you can shed some light. thx


Ok sure. Carbon filters out long-chain organics. Small molocules
pass tight through. In practical terms if you add say methylene
blue to the water and it's dark blue, carbon will filter that
out quite quickly.

But, if you were say to add salt to the tank, carbon wouldn't
touch it. It does not remove salt.

There are no hard and fast rules about this, but in a very rough
sense, rely on carbon not to remove anything transparent, but any
chemical "big" enouh to have color - well that will be filtered out
by carbon.

Melafix is good stuff, but it smells and looks like something that
would be filtered out by carbon. Not so fertilizers.

Having said that there are people who believe carbon will take
things ouf of the water like copper, iron and the like and its
no good for plants. This is slightly true. Carbon will remove
minicsule amnounts of these thigs, so if you never change water
and use carbon for months the plants may suffer. OTOH I've done
this and if they suffer it's really not so you'd notice.

I"ve read the above three or four times and I'd like to condense and
paraphrase it for my own clarity. Carbon in a filter will not filter
clear liquid plant food, including the Leaf Zone Iron and Potassium
that I add once a week to my planted tanks. The miniscule amount of
trace elements that carbon may possibly remove will be replenished by
the fresh water introduced in regular weekly 20% water changes. Is
this correct? If so, you've just saved me valuable time that would
have been taken up reading every plant book I own from cover to cover
for the umteenth time. If this is not correct then it's back to square
one.

Mr Gardener

Cycling and Bio-Filter in Planted Tank
 

I"ve read the above three or four times and I'd like to condense and
paraphrase it for my own clarity. Carbon in a filter will not filter
clear liquid plant food, including the Leaf Zone Iron and Potassium
that I add once a week to my planted tanks. The miniscule amount of
trace elements that carbon may possibly remove will be replenished by
the fresh water introduced in regular weekly 20% water changes. Is
this correct? If so, you've just saved me valuable time that would
have been taken up reading every plant book I own from cover to cover
for the umteenth time. If this is not correct then it's back to square
one.

Basically corect. It will absolutely not remove any Potassium
Nitrate, Potassium Monophosphate or Potassium Sulphate which
are the traditional sources of N, P and K.

Iron and trace elements? Nope, they won't be filtered out either.

Wel, ABOUT that iron. It's usually chelated and the chelate is
a long chain organic and it seems likely this can be filtered
out, to some extent at least, by carbon. Although how much I
do not know. I *think* it's pretty negligable and if you dose
regularly it should not be a problem.

Now, my water comes out of the tap at 3.0 ppm unchealted. Tom
Barr's target is .3 ppm.

However if you look in the Dupla book "The Optimum Aquarium"
they measure the water the took crypts from in Asia at 3.0 ppm
unchelated iron and 3.0 ppm chelated iron. I change water
a lot and have good luck with crypts.

So I'm the wrong person to ask about iron!

Iron test kits (unlke nitrate test kits) are pretty accurate
so at worst you can measure for yourself what the carbon is
doing.

--
Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net