Could it be the substrate? Tank in terminal decline...

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... There are dosing calculators you can use, like <"Rotala Butterfly">, or the method in the <"FeEDDHA"> thread....
Hi,
The Rotala Butterfly calculator doesn't have the Chempak Sequestered Iron ( with Magnesium and Manganese ), it has DTPA 10%,11% and 8% but the one I've got says it DTPA 1.2% and it has options for EDDHA Fe 6% but I have 0.8% ? It says it's total iron soluble in water is 2.0% on the box. The warning on the box says says it contains Manganese Sulphate which is "harmful to aquatic life" so I'm getting nervous as I have fish in there.

I tried to read the other thread but I found it overwhelming, I'm an artist I haven't done "science" for 27 years. If it didn't have discus fish in it I could experiment more but I don't want to kill anything.

It says in the thread - "You know how much iron (in ppm = mg/L) you've added from the percentage of iron in the compound (6% for FeEDDHA), how many grams you've added and the volume of the aquarium. You can use one of the <"online calculators">, if you aren't confident about your calculations."

So I think if I put 1 gram per litre of Chempak in the water I will end up with 120ug of DPTA and 80ug of EDDHA in each litre of water in the tank?
In the thread FishWorks writes about aiming for !ppm of Fe DPTA, I presume I should put 10 grams of Chempak per litre then, seems a hell of a lot? Also do I ignore the EDDHA? I'm baffled!

What I have learnt is that I've been dosing my chelated trace hugely ineffectively because I found that if I kept my ferts in a cupboard I would forget to put them in so I've been storing them in almost direct sunlight for donkies. Because it didn't say in the instructions I had to keep them out of the light I assumed this was ok, but if it becomes unavailable to the plants in 30 mins of contact with light (in the tank) then my stuff has been unavailable way before it gets in the tank. I'm not quite sure how I managed to grow anything!
 

dw1305

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Hi all,
I presume I should put 10 grams of Chempak per litre then, seems a hell of a lot? Also do I ignore the EDDHA? I'm baffled!
Yes, you don't need anything like that amount.
DTPA 1.2% and it has options for EDDHA Fe 6% but I have 0.8% It says it's total iron soluble in water is 2.0% on the box
That is fine, you only need to know the percentage of each nutrient and the volume of the tank.
I'm an artist I haven't done "science" for 27 years. If it didn't have discus fish in it I could experiment more but I don't want to kill anything.
Point taken, it is really easy to get lost in the powers of 10, I do it quite often.

We just need to make sure we don't get anywhere near adding a toxic dose of iron (Fe) or manganese (Mn).

The important bits we have are:
  • Tank is 450 litres
  • We are aiming for 0.5 ppm iron
  • Your fertiliser contains 2% Fe
I'll put the stages I used in below

Some "powers of 10" bits
Parts per million is the same unit as mg/L, so there are a million (10^6) milligrams in a Kg/litre (of water). One gram is 1000 (10^3) milligrams, and there are 1000 (10^3) grams in a litre (of water). Add the two power of 10 together and you get 10^6.

1% is equal to 10,000 mg/L (100*10,000 = 1,000,000), again easier in the powers of 10, 10^4 + 10^2 = 10^6 and 2% Fe is equal to 20,000 ppm.

The Fertiliser bit
So our fertiliser has 20,000 ppm of Fe. If we take 1g of "Chempak sequestered iron" and add it to 1 litre of water, we've divided 20,000/100, so we have 20 ppm Fe.

We want 0.5 ppm, which is equivalent to 1g in 40 litres (20/0.5 = 40).

You have a 450 litre tank, so we can multiply by 10 to give us how we would need in 400 litres of water: 1g x 10 = 10g and then add add on the amount we would need for the extra 50 litres, = 1.25g (40 x 1.25)

Total amount of "Chempak sequestered iron" to give ~0.5 ppm = 11.25g in 450 litres.

Check
I like to check, and I'm still going to use <"Rotala Butterfly"> and the 10% FeDTPA solution. We know that the 10% FeDTPA is 5 times more concentrated than the iron source we have. If I aim for 2.5 ppm (0.5 x 5) in the calculator, it should give me 11.25g as the answer (below).

Rotala_FeDTPA.JPG

cheers Darrel
 

dw1305

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Hi all,
it is really easy to get lost in the powers of 10, I do it quite often
That is both "I do this sort of calculation" and "I get lost in the powers of 10" quite frequently.
If we take 1g of "Chempak sequestered iron" and add it to 1 litre of water, we've divided 20,000/100, so we have 20 ppm Fe.
I like to check
You check through your post and then this is, honestly, just <"careless typing">, it should be "20,000/1000 = 20 ppm".

cheers Darrel
 
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Cat

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Hi all,Yes, you don't need anything like that amount. That is fine, you only need to know the percentage of each nutrient and the volume of the tank. Point taken, it is really easy to get lost in the powers of 10, I do it quite often.

We just need to make sure we don't get anywhere near adding a toxic dose of iron (Fe) or manganese (Mn).

The important bits we have are:
  • Tank is 450 litres
  • We are aiming for 0.5 ppm iron
  • Your fertiliser contains 2% Fe
I'll put the stages I used in below

Some "powers of 10" bits
Parts per million is the same unit as mg/L, so there are a million (10^6) milligrams in a Kg/litre (of water). One gram is 1000 (10^3) milligrams, and there are 1000 (10^3) grams in a litre (of water). Add the two power of 10 together and you get 10^6.

1% is equal to 10,000 mg/L (100*10,000 = 1,000,000), again easier in the powers of 10, 10^4 + 10^2 = 10^6 and 2% Fe is equal to 20,000 ppm.

The Fertiliser bit
So our fertiliser has 20,000 ppm of Fe. If we take 1g of "Chempak sequestered iron" and add it to 1 litre of water, we've divided 20,000/100, so we have 20 ppm Fe.

We want 0.5 ppm, which is equivalent to 1g in 40 litres (20/0.5 = 40).

You have a 450 litre tank, so we can multiply by 10 to give us how we would need in 400 litres of water: 1g x 10 = 10g and then add add on the amount we would need for the extra 50 litres, = 1.25g (40 x 1.25)

Total amount of "Chempak sequestered iron" to give ~0.5 ppm = 11.25g in 450 litres.

Check
I like to check, and I'm still going to use <"Rotala Butterfly"> and the 10% FeDTPA solution. We know that the 10% FeDTPA is 5 times more concentrated than the iron source we have. If I aim for 2.5 ppm (0.5 x 5) in the calculator, it should give me 11.25g as the answer (below).

View attachment 127424
cheers Darrel

Thank you SO much for clearing everything up! I asked my husband to help because I couldn't even manage the ppm = mg/litre and despite being an electronic engineer he still got it wrong. Always doing these things late at night after children and general stuff is my excuse. Because of everything I read I put the ferts in the dark somewhere and now I can't find them, which is typical, so they missed their trace ferts today. So I'm probably going to end up spending all of tomorrow trying to find it but at least I can say they are dam well going to get some iron!
 

dw1305

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Hi all,
Thank you SO much for clearing everything up!
That is all right, I went through the steps in the post, but I already knew the answer was about 10g of EDTA from a quick bit of guesstimation.
Because of everything I read I put the ferts in the dark somewhere and now I can't find them
Been there, done that.

It is only really the iron chelates (FeEDTA & FeDTPA ) that photo-degrade. You can use a brown glass bottle (or wrap aluminium foil around a clear one) if that makes life easier.

The FeEDDHA, isn't effected by light (it is a <"pink solution">, as long as it is pink the iron is still bound).

cheers Darrel
 

Cat

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Just to be clear do I presume I add this three times a week when I add my usual trace ferts?

It does seem unlikely if iron is so easy turned into a form that makes it unavailable for plants that my enriched substrate could have been making up for my inadequate fertilising previously. So ultimately I don't know whats going on. Most people seem concerned with CO2 but if my duckweed died as well and presumably sits on the surface and therefore has a better source of CO2 from the air rather than water wouldn't that imply it wasn't a CO2 problem? Isn't that what the duckweed formula is all about, trying to isolate one variable from another? ( By the way we always called it chickweed? It come from my pond by accident but I presume its the same thing, it was a pain in the blahblahblahblah when it was alive).

Sorry more questions!
 

dw1305

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Hi all,
It does seem unlikely if iron is so easy turned into a form that makes it unavailable for plants that my enriched substrate could have been making up for my inadequate fertilising previously.
Slightly different in the substrate, some iron compounds may be reduced in anaerobic conditions and become plant available again. This is particularly likely to occur in the zones of <"fluctuating REDOX that surround roots">.
Just to be clear do I presume I add this three times a week when I add my usual trace ferts?
Once a week should be fine for starters.
Most people seem concerned with CO2 but if my duckweed died as well and presumably sits on the surface and therefore has a better source of CO2 from the air rather than water wouldn't that imply it wasn't a CO2 problem? Isn't that what the duckweed formula is all about, trying to isolate one variable from another?
That is exactly it, floating plants have access to aerial CO2 and first dibs on light.

cheers Darrel


.
 

Cat

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Hi all, Slightly different in the substrate, some iron compounds may be reduced in anaerobic conditions and become plant available again. This is particularly likely to occur in the zones of <"fluctuating REDOX that surround roots">. Once a week should be fine for starters. That is exactly it, floating plants have access to aerial CO2 and first dibs on light.

cheers Darrel


.
Thank you for your reply, for some reason I didn't get an alert about it or I would have replied earlier. I'm glad once a week is enough as my tank still looks like the amazon three days later! It's quite a different colour and I'm wondering if It's ever going to go back to normal. The fish seem happier bizarrely, I know Discus would traditionally live in dark water but these are bred in Germany in hard water, maybe their instincts are coming through despite years of breeding. I'll have a read of fluctuating Redox and try and educate myself further. It's funny because partly why I have kept going with the tank despite not really having the time is because I thought it made for a great learning opportunity for my children even if it is because of them I don't have the time for it!
 

dw1305

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Hi all,
I'll have a read of fluctuating Redox and try and educate myself further.
I've got a few papers looking at using aquatic plants, in constructed wetlands, to treat wastewater. Unfortunately I haven't managed to find a more user friendly aquarium based version.

There is a Danish Academic, <"Ole Pedersen">, who both works in this field and keeps planted aquariums. He has written some bits for <"TAG">, but I'm not a member and I haven't read them. There is also an <"article by Stephan Tanner"> (another academic and owner of "Swiss Tropicals"), but it doesn't talk about plants.

These are two recent papers, <"Enhancement of facultative anaerobic denitrifying communities by oxygen release from roots of the macrophyte in constructed wetlands">, but it isn't open source (I can get a pdf if any-one wants one?). This next one is open source.
<"Myriophyllum aquaticum Constructed Wetland Effectively Removes Nitrogen in Swine Wastewater">.

The sort of search terms you need (in Google Scholar) are "Radial Oxygen Loss (ROL)", "Constructed Wetlands" and "Rhizosphere".
It's quite a different colour and I'm wondering if It's ever going to go back to normal.
The <"pink tint"> should fade over time. I'd actually use it as an indication of when to add iron chelate.
The fish seem happier bizarrely, I know Discus would traditionally live in dark water but these are bred in Germany in hard water, maybe their instincts are coming through despite years of breeding.
I would expect all Discus to be happier in tinted soft water, even ones bred to look like fluorescent dinner plates.
It's funny because partly why I have kept going with the tank despite not really having the time is because I thought it made for a great learning opportunity for my children even if it is because of them I don't have the time for it!
I think they are a great aid to <"learning"> and teaching at all sorts of different levels, my <"children"> (<"and pets">) have really enjoyed the tanks at home.

cheers Darrel
 

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I would expect all Discus to be happier in tinted soft water, even ones bred to look like fluorescent dinner plates.

Are you calling my fish gaudy? Obviously I'm deeply offended....no seriously if I was a user of emoticons I would have put one crying with laughter here but I feel too old for such things.

So I've learnt what REDOX is now, and I read - <"Myriophyllum aquaticum Constructed Wetland Effectively Removes Nitrogen in Swine Wastewater">. Most of which went straight over my head although it does seem that Myriophyllum aquaticum is great for reducing green house gases and does a lot of good in soil if you are looking particularly for denitrifying bacteria? Still it will be interesting to see if essentially iron has been my problem, what ever it is it has just stopped the plants reproducing and fundamentally thats why my tank is dying.
 

dw1305

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Hi all,
Are you calling my fish gaudy?
No, it wasn't intended as a criticism of your lovely Discus. Personally I'm a wild type "tabby" fish liker, but even I don't object to a bit of colour enhancement.
I don't understand all of it either. I think the important bit is that the roots are leaky structures and produce much more complex microbial zonation in the sediment. The relevant bit would be:
......To determine whether this high efficiency was associated with the performance of active microbes, the abundance, structure, and interactions of microbial community were compared in the unvegetated and vegetated samples........that M. aquaticum greatly changed the microbial community, and ammonium oxidizers (Nitrosospira and Nitrososphaera), nitrite-oxidizing bacteria (Nitrospira), and abundant denitrifiers including Rhodoplanes, Bradyrhizobium, and Hyphomicrobium, were enriched significantly in the sediments.....
So basically the vegetated samples had a much greater diversity of microbes, for all parts of the nitrification/denitrification cycle.
Still it will be interesting to see if essentially iron has been my problem
Fingers crossed, unfortunately you have to wait a bit with iron (Fe), because it isn't mobile within the plant and only new <"leaves will be greener and healthier">.

cheers Darrel
 

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