Hi all,
I've recently started testing iron in my 75 gal planted tank (4x55 watt
CF 5000K). I've got a medium plant load, I think - 2 large, 4 medium,
5-6 small, swords and anubias and java ferns mostly, and some floating
hornwort that I cut back weekly to just fill in the spaces (fish = 30
neons, 2 discus, and a few bottom-dweller-scum-eating-types). A little
hair algae, not too much though. Twice weekly I use Seachem's flourish
micronutrient supplement.
So, my Iron was undetectabe using the seachem test kit, and I've been
adding their Iron every day now, in addition to the twice weekly
flourish. Immediately after dosing (5 mL) in the morning, Iron levels
are skyhigh (.8 mg/L, or whatever the scale is). 2 hours later, it's
down to normal (~.1mg/L). By the next morning, it's zero/undetectable again.
It's a little early to say how this is affecting the plants, I've only
been doing this for a week, but what I'm wondering is if this is normal
Iron chemistry? it seems to be really volatile. I don't have any
laterite in the tank or anything, just old crappy gravel from long ago.
Could this have something to do with the dechlorinator I use? It says
"detoxifies heavy metals" on it - could my tank be saturated with some
Iron chelator or something?

How crazy are your Iron fluctuations?

Thanks

-Stephane

stephane wrote in message ...
Hi all,
I've recently started testing iron in my 75 gal planted tank (4x55 watt
CF 5000K). I've got a medium plant load, I think - 2 large, 4 medium,
5-6 small, swords and anubias and java ferns mostly, and some floating
hornwort that I cut back weekly to just fill in the spaces (fish = 30
neons, 2 discus, and a few bottom-dweller-scum-eating-types). A little
hair algae, not too much though. Twice weekly I use Seachem's flourish
micronutrient supplement.
So, my Iron was undetectabe using the seachem test kit, and I've been
adding their Iron every day now, in addition to the twice weekly
flourish. Immediately after dosing (5 mL) in the morning, Iron levels
are skyhigh (.8 mg/L, or whatever the scale is). 2 hours later, it's
down to normal (~.1mg/L). By the next morning, it's zero/undetectable again.
It's a little early to say how this is affecting the plants, I've only
been doing this for a week, but what I'm wondering is if this is normal
Iron chemistry? it seems to be really volatile. I don't have any
laterite in the tank or anything, just old crappy gravel from long ago.
Could this have something to do with the dechlorinator I use? It says
"detoxifies heavy metals" on it - could my tank be saturated with some
Iron chelator or something?

How crazy are your Iron fluctuations?

Thanks

-Stephane


Similar.
Iron complexes with about 10-20 inorganic chemicals, and more organic
chemicals or precipitates out of solution, determining how much you
need for your plants, the bioavailabilty, test kits are not very
useful.

A better approach is make sure you have good CO2/NO3/K/PO4 and GH
levels.
If these are kept in good shape, then you can add a known amount
Flourish to a known volume of water. Generally, I've found 5mls 3x a
week per 20-30gallon to be sufficent even at high light, depending on
plant biomass in the tank.
You can split this up to daily dosing etc, but this path will build on
itself startying with good CO2 and working your way downward to the
micro nutrients.

I have a 75 gal and use Flourish also, I add 15-20mls every other day
but I have 330w of light. I'd try at least 10mls 3x a week if you have
decent plant biomass.

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

This should clear up a fair amount for you.
The other issue is that recommendations are often for not as densely
planted, CO2 enriched high light tanks. So adding 2-4x the amount is
not uncommon, Claus from Tropica, about adding Tropica Master Grow
said what I added was normal although it's not as rich iron wise as
TMG.

Regards,
Tom Barr

" wrote in message
om...

[ ... ]

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

What source do you use for K+ ?
Thanks Tom.

" wrote in message
om...

[ ... ]

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

What source do you use for K+ ?
Thanks Tom.

" wrote in message
om...

[ ... ]

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

What source do you use for K+ ?
Thanks Tom.

"Nemo" wrote in message ...
" wrote in message
om...

[ ... ]

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

What source do you use for K+ ?
Thanks Tom.

KNO3, you can use K2SO4 if you want independent control of K+ without
affecting NO3/PO4. I also get a little K+ from KH2PO4, I do not need
to dose any K2SO4 since I get most of the K from KNO3 I need to
support good plant growth. Most folk's planted tanks are like this
unless they have a load of fish, high NO3 in their tap etc then adding
K2SO4 or KCl is added in place of the KNO3.

So in most cases, folks get enough K+ from the KNO3, roughly 4x the
amount of K relative to N. So there will always be an excess of K if
you have a moderate fish load, good plant growth, low NO3 in thr tap
water etc.


Regards,
Tom Barr

"Nemo" wrote in message ...
" wrote in message
om...

[ ... ]

Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm and the GH at
5 or higher degrees. CO2 at 20-30ppm while the lights are on. Test the
pH in the am and the pm to make sure/certain there is plenty of CO2 in
there.
You use CO2?

What source do you use for K+ ?
Thanks Tom.

KNO3, you can use K2SO4 if you want independent control of K+ without
affecting NO3/PO4. I also get a little K+ from KH2PO4, I do not need
to dose any K2SO4 since I get most of the K from KNO3 I need to
support good plant growth. Most folk's planted tanks are like this
unless they have a load of fish, high NO3 in their tap etc then adding
K2SO4 or KCl is added in place of the KNO3.

So in most cases, folks get enough K+ from the KNO3, roughly 4x the
amount of K relative to N. So there will always be an excess of K if
you have a moderate fish load, good plant growth, low NO3 in thr tap
water etc.


Regards,
Tom Barr

I don't think that's quite right.

You cannot use KNO3 purely as your source of Kwithout using something like
KCl or K2SO4

It is not correct to say that there is 4x K compared to NO3. (I presume you
are using molecular mass)

If you dose KNO3 to obtain nitrates of, say, 10ppm, your K will be less than
10ppm. Now, I am sure this is fine for plants to grow, but your opening
statement says "Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm"

To achieve your quoted ratio, you will need KCl or K2SO4


What source do you use for K+ ?
Thanks Tom.

KNO3, you can use K2SO4 if you want independent control of K+ without
affecting NO3/PO4. I also get a little K+ from KH2PO4, I do not need
to dose any K2SO4 since I get most of the K from KNO3 I need to
support good plant growth. Most folk's planted tanks are like this
unless they have a load of fish, high NO3 in their tap etc then adding
K2SO4 or KCl is added in place of the KNO3.

So in most cases, folks get enough K+ from the KNO3, roughly 4x the
amount of K relative to N. So there will always be an excess of K if
you have a moderate fish load, good plant growth, low NO3 in thr tap
water etc.

You cannot use KNO3 purely as your source of K without using something like
KCl or K2SO4

Well many folks have for quite some time.
Also see APD recent post where I discussed this.

It is not correct to say that there is 4x K compared to NO3. (I presume you
are using molecular mass)

Well actually it is. But I did not say that with respect to NO3. I
said 4x as much with respect to N relative to K+.
Re read the post.

It is quite correct as far uptake and plant biomass. A plant has
roughly 1.5% dry weight as N. It has roughly 1% as K+. See Epstein
1972 for a reference to support this dry weight mass.

N = NO3 when using KNO3.
So taking the N moles it becomes 14g mol N/62g mol NO3= .22 moles of N
in each mole of NO3.

So now since it's 1.5% vs 1 %, this becomes 1.5 N/1 K= 1.5/.22 moles=
6.8x more need per mole.

Since we use KNO3:
KNO3 is 101.1g mol. K+ represents 39% of this mass. N represents 61%.
61/39= 1.56. 6.8/1.56= 4.3 x more K+ than N needs per mole of KNO3
added.

So yes, it is correct in saying that you don't need to add more K+
sources, even if you consider fish waste and other sources of N.

Unless you are adding susbtantial inputs of NO3 from fish or from the
tap water, most folks don't need to add K2SO4 or KCL.
Which is what I said to begin with.

Even if a plant has more, needs more K relative to N and other
variations are considered, 4.3x as much is such a large factor that K+
will not become limiting in most planted tanks using KNO3.

If you dose KNO3 to obtain nitrates of, say, 10ppm, your K will be less than
10ppm. Now, I am sure this is fine for plants to grow, but your opening
statement says "Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm"

To achieve your quoted ratio, you will need KCl or K2SO4

After a couple of doses it will be close to this since the amount of N
actually used relative to K is higher, leaving more K+ behind as the
plants remove more N. Folks will often re set their tank(some less
frequently than other etc which would mean more build up of K,
relative to N)

It's an ideal ratio that adds K+ to a slight excess but few test for
K+. If someone is off by a few ppm on the K+ either way they are fine.
A Generalized ratio is 10-1-10. There's some excess as far as K+ using
this ratio.

None of these levels/paramaters are set in stone and are only a snap
shot in time, if a range is kept, then the plant's needs are met and
they grow well, they do not have to have a precise ratio or level.
No need for folks to be obsessive or freak out if the range is off by
1-2ppm with K or N.
It will not make or break plant tanks using KNO3.

My point is that most folks don't need to add KCL and K2SO4 if they
use KNO3 unless they have high NO3 tap water or a high fish load, non
CO2 methods generally don't use KNO3 since less mainteance and less/no
dosing besides fish food is often the goal there.

But will adding some extra K+ from K2SO4 or KCL hurt? No. My point is
that's most likely not needed though and is one less thing to buy and
dose.

Regards,
Tom Barr

You cannot use KNO3 purely as your source of K without using something like
KCl or K2SO4

Well many folks have for quite some time.
Also see APD recent post where I discussed this.

It is not correct to say that there is 4x K compared to NO3. (I presume you
are using molecular mass)

Well actually it is. But I did not say that with respect to NO3. I
said 4x as much with respect to N relative to K+.
Re read the post.

It is quite correct as far uptake and plant biomass. A plant has
roughly 1.5% dry weight as N. It has roughly 1% as K+. See Epstein
1972 for a reference to support this dry weight mass.

N = NO3 when using KNO3.
So taking the N moles it becomes 14g mol N/62g mol NO3= .22 moles of N
in each mole of NO3.

So now since it's 1.5% vs 1 %, this becomes 1.5 N/1 K= 1.5/.22 moles=
6.8x more need per mole.

Since we use KNO3:
KNO3 is 101.1g mol. K+ represents 39% of this mass. N represents 61%.
61/39= 1.56. 6.8/1.56= 4.3 x more K+ than N needs per mole of KNO3
added.

So yes, it is correct in saying that you don't need to add more K+
sources, even if you consider fish waste and other sources of N.

Unless you are adding susbtantial inputs of NO3 from fish or from the
tap water, most folks don't need to add K2SO4 or KCL.
Which is what I said to begin with.

Even if a plant has more, needs more K relative to N and other
variations are considered, 4.3x as much is such a large factor that K+
will not become limiting in most planted tanks using KNO3.

If you dose KNO3 to obtain nitrates of, say, 10ppm, your K will be less than
10ppm. Now, I am sure this is fine for plants to grow, but your opening
statement says "Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm"

To achieve your quoted ratio, you will need KCl or K2SO4

After a couple of doses it will be close to this since the amount of N
actually used relative to K is higher, leaving more K+ behind as the
plants remove more N. Folks will often re set their tank(some less
frequently than other etc which would mean more build up of K,
relative to N)

It's an ideal ratio that adds K+ to a slight excess but few test for
K+. If someone is off by a few ppm on the K+ either way they are fine.
A Generalized ratio is 10-1-10. There's some excess as far as K+ using
this ratio.

None of these levels/paramaters are set in stone and are only a snap
shot in time, if a range is kept, then the plant's needs are met and
they grow well, they do not have to have a precise ratio or level.
No need for folks to be obsessive or freak out if the range is off by
1-2ppm with K or N.
It will not make or break plant tanks using KNO3.

My point is that most folks don't need to add KCL and K2SO4 if they
use KNO3 unless they have high NO3 tap water or a high fish load, non
CO2 methods generally don't use KNO3 since less mainteance and less/no
dosing besides fish food is often the goal there.

But will adding some extra K+ from K2SO4 or KCL hurt? No. My point is
that's most likely not needed though and is one less thing to buy and
dose.

Regards,
Tom Barr

You cannot use KNO3 purely as your source of K without using something like
KCl or K2SO4

Well many folks have for quite some time.
Also see APD recent post where I discussed this.

It is not correct to say that there is 4x K compared to NO3. (I presume you
are using molecular mass)

Well actually it is. But I did not say that with respect to NO3. I
said 4x as much with respect to N relative to K+.
Re read the post.

It is quite correct as far uptake and plant biomass. A plant has
roughly 1.5% dry weight as N. It has roughly 1% as K+. See Epstein
1972 for a reference to support this dry weight mass.

N = NO3 when using KNO3.
So taking the N moles it becomes 14g mol N/62g mol NO3= .22 moles of N
in each mole of NO3.

So now since it's 1.5% vs 1 %, this becomes 1.5 N/1 K= 1.5/.22 moles=
6.8x more need per mole.

Since we use KNO3:
KNO3 is 101.1g mol. K+ represents 39% of this mass. N represents 61%.
61/39= 1.56. 6.8/1.56= 4.3 x more K+ than N needs per mole of KNO3
added.

So yes, it is correct in saying that you don't need to add more K+
sources, even if you consider fish waste and other sources of N.

Unless you are adding susbtantial inputs of NO3 from fish or from the
tap water, most folks don't need to add K2SO4 or KCL.
Which is what I said to begin with.

Even if a plant has more, needs more K relative to N and other
variations are considered, 4.3x as much is such a large factor that K+
will not become limiting in most planted tanks using KNO3.

If you dose KNO3 to obtain nitrates of, say, 10ppm, your K will be less than
10ppm. Now, I am sure this is fine for plants to grow, but your opening
statement says "Keep the NO3/K+/PO4 in good shape, 10ppm/10ppm/.5-1.0ppm"

To achieve your quoted ratio, you will need KCl or K2SO4

After a couple of doses it will be close to this since the amount of N
actually used relative to K is higher, leaving more K+ behind as the
plants remove more N. Folks will often re set their tank(some less
frequently than other etc which would mean more build up of K,
relative to N)

It's an ideal ratio that adds K+ to a slight excess but few test for
K+. If someone is off by a few ppm on the K+ either way they are fine.
A Generalized ratio is 10-1-10. There's some excess as far as K+ using
this ratio.

None of these levels/paramaters are set in stone and are only a snap
shot in time, if a range is kept, then the plant's needs are met and
they grow well, they do not have to have a precise ratio or level.
No need for folks to be obsessive or freak out if the range is off by
1-2ppm with K or N.
It will not make or break plant tanks using KNO3.

My point is that most folks don't need to add KCL and K2SO4 if they
use KNO3 unless they have high NO3 tap water or a high fish load, non
CO2 methods generally don't use KNO3 since less mainteance and less/no
dosing besides fish food is often the goal there.

But will adding some extra K+ from K2SO4 or KCL hurt? No. My point is
that's most likely not needed though and is one less thing to buy and
dose.

Regards,
Tom Barr

It seems from posts that people in your position ended up finding that
adding some extra K resulted in dramatic improvement. I think this is why
the popular PMDD formula has and continues to advocate adding K+ as Cl or
KSO4.

KNO3 would then be the "optional" chemical if there's a low fish load or
low NO3 in tap water.

Even if a plant has more, needs more K relative to N and other
variations are considered, 4.3x as much is such a large factor that K+
will not become limiting in most planted tanks using KNO3.

Plants use iron (among other things) to make chlorophyll.

Moon
I breed dwarf crayfish for planted aquariums and grow trees in aquariums.
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