# [Wet Thumb Forum]-trace dosing - PMDD or Flourish?



## aviel (Sep 12, 2004)

Roger,

I just discovered that there's a big difference between the PMDD dosing rate and the Seachem Flourish dosing rate or micros (excluding iron) - that is PMDD are dosing depending on the specific chemical sometimes 6.6 X and sometime 100X times. So my question is whether PMDD is overdosing or Seachem is under dosing... I use CSM+B and my dosing rate ressembles PMDD - so maybe I am overdosing? toxicity, etc???? 



Here's the numbers - 

PMDD are saying to take 9g into 300mL water, then use 1mL for every 10L every water change.
Seachem are saying to take 5mL per 250L once or twice a week.

PMDD(%) ppm per day Flourish ppm per day PMDD / flourish
Mn 2	0.008571429 0.0118	0.000505714 16.94915254
Zn 0.4	0.001714286 0.0007	0.00003 57.14285714
Cu 0.1	0.000428571 0.0001	4.28571E-06 100
Mo 0.06	0.000257143 0.0009	3.85714E-05 6.666666667
B 1.3	0.005571429 0.009	0.000385714 14.44444444

Since the table here is corrupted - just one example - according to this using my CSM+B dosing scheme I am dosing Boron 14.444 times more than someone who is using Seachem Flourish recommended dose.

Aviel.


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## aviel (Sep 12, 2004)

Roger,

I just discovered that there's a big difference between the PMDD dosing rate and the Seachem Flourish dosing rate or micros (excluding iron) - that is PMDD are dosing depending on the specific chemical sometimes 6.6 X and sometime 100X times. So my question is whether PMDD is overdosing or Seachem is under dosing... I use CSM+B and my dosing rate ressembles PMDD - so maybe I am overdosing? toxicity, etc???? 



Here's the numbers - 

PMDD are saying to take 9g into 300mL water, then use 1mL for every 10L every water change.
Seachem are saying to take 5mL per 250L once or twice a week.

PMDD(%) ppm per day Flourish ppm per day PMDD / flourish
Mn 2	0.008571429 0.0118	0.000505714 16.94915254
Zn 0.4	0.001714286 0.0007	0.00003 57.14285714
Cu 0.1	0.000428571 0.0001	4.28571E-06 100
Mo 0.06	0.000257143 0.0009	3.85714E-05 6.666666667
B 1.3	0.005571429 0.009	0.000385714 14.44444444

Since the table here is corrupted - just one example - according to this using my CSM+B dosing scheme I am dosing Boron 14.444 times more than someone who is using Seachem Flourish recommended dose.

Aviel.


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## gpodio (Feb 4, 2004)

All fertilizers differ somewhat, plus not many people use the recommended doses so differences may even be greater. Both CSM+B and Flourish seem to work so my guess is that neither are underdosing nor overdosing, perhaps most of these elements can be present in a wide range of values safely.

Not sure if this helps any but it's a similar comparison:
http://www.gpodio.com/fert_table.asp
http://www.gpodio.com/fert_table_st.asp

Giancarlo Podio


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## aviel (Sep 12, 2004)

Hi,

Differentiation of 20%, 30% makes sense - but times 5, time 14, times 100 does not! 

As for the links - they just provide the percentage in the products - this should still be multiplied by the dosing regime. And this is exactly what I have done.

Aviel.


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## gpodio (Feb 4, 2004)

The second link provides values standardised on FE contents and below that the iron levels based on suggested doses. Personally I don't see anything that is 100 times based on recommended dosing, are you calculating the dilution of CSM+B as well? Anyway, it's not like there's a ton of something in one and a gram in the other. We're talking very small percentages here so even 100 times is still a small number in many cases and probably well within the acceptable range.

The fact that both work even when recommended doses are multiplied by 4-5 times should help support this assumption. I think it's safe to use either, personally I've seen better results using Flourish however the cost difference is quite big.

Regards
Giancarlo Podio


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## aviel (Sep 12, 2004)

> quote:
> 
> The second link provides values standardised on FE contents and below that the iron levels based on suggested doses.


I don't think standardizing around Fe content matters - no one said that both vendors shoot for the same iron dosing. In fact, this is exactly what I want to learn - how much do they recommend to dose for each and every ingredient (including Fe). Moreover, for Iron Seachem are offering the flourish iron supplement which makes the relative part of other chemical even lower.



> quote:
> 
> Personally I don't see anything that is 100 times based on recommended dosing, are you calculating the dilution of CSM+B as well?


Look at the Copper - 9 grams of CSM+B provides 9*0.1% = 0.009 g Copper. Diluting this by 1/300 like they recommend gives 0.00003 g Copper and dosing it to 10L give 0.00003 mg / 10000 mg = 0.03 ppm per dose = 0.0042 ppm per day.

5 ml of Flourish provides 5 ml *0.0001% = 0.000005 ml copper. Per 250L this gives 0.000005 ml / 250,000 ml = 0.00002 ppm per dose. Once or twice a week translates to 0.000004 ppm per day.

Looks like PMDD suggest 1000X the amount of copper that Flourish recommends...



> quote:
> 
> We're talking very small percentages here so even 100 times is still a small number in many cases and probably well within the acceptable range.


That same argument you could say about dosing 200 ppm NO3... vs dosing 2 ppm NO3. It's one millionth... - it's very small. It wouldn't make any harm.



> quote:
> 
> The fact that both work even when recommended doses are multiplied by 4-5 times should help support this assumption.


I am not sure about my CSM+B dosing regime. How much CSM+B do you dose? Do you supplement iron on top of that of the CSM+B?



> quote:
> 
> personally I've seen better results using Flourish however the cost difference is quite big.


Flourish contains more goodies than just trace so you are not comparing apples to apples. However I am still afraid that I am overdosing CSM+B.

And all of this discussion just because of my ugly Macrandra....







oh boy...

Aviel.


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## Roger Miller (Jun 19, 2004)

Aviel,

I find the trace doses provided by Flourish to be very low. I use Flourish Trace. I started with a low dose and increased the dose a couple times to cure problems. I also use Flourish Iron. I don't mix iron with other traces or link my iron doses to my trace doses in any way.

I think it's a bad idea to use iron as an indicator for other trace element levels. The chemistry of chelated iron -- and especially of chelated ferric iron -- is *very* different from the chemistry of other trace elements. You can get yourself in either of two extreme conditions depending on the details of your tank; iron levels seem high while other trace metals are too low for the health of plants or iron levels seem low but other trace metals are at levels toxic to plants. Or it could work. It's a role of the dice.

Boron and most -- perhaps all -- of the trace metal nutrients are toxic to plants, fish and other critters. Crustaceans are probably the most sensitive, but that isn't universally true. For instance, Jordanella floridae is very sensitive to zinc. For most organisms the earliest sign of toxicity is probably going to be reproductive failure in one form or another; failure to breed successfully, failure of eggs to hatch, failure of young to survive, and so on.

Because of trace nutrient toxicity I think it is a good policy to minimize your trace doses. For instance, EPA claims that 1 mg/l of total iron (including colloids, chelates, complexes and free ions) is toxic to sensitive organisms. I noticed earlier that the daily doses of iron that you were planning could have your tank exceeding 1 mg/l of total iron very quickly.

Boron is another good example. Boron is toxic to some plants at levels under 0.6 mg/l. Most water supplies have more than enough boron to provide for the needs of plants, so boron should be dosed *very* conservatively -- probably not at all unless you are using RO water.

Copper and zinc are more complicated. They can be toxic at low concentrations, but their toxicity depends on the presence of complexing agents -- mostly carbonates and organics. If your water is very soft, you have an inorganic substrate and you do large water changes then you may need to worry about those metals becoming toxic. If you have hard water then maybe you don't need to worry very much about it.

I do not use PMDD and never have, so I avoid answering questions about it. I did once calculate the dose of CSM that would exceed toxic copper levels for water in Vancouver, BC (soft water). The dose was very small.


Roger Miller


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## aviel (Sep 12, 2004)

Roger,

Thanks for the information. I now re-calculated and it seems like flourish trace and plantex CSM+B are much closer now except for the Boron!!! When all other ingredients are "normalized" - CSM+B boron concentration is 14X than that of the seachem. I should have purchased the CSM without B (I don't know where to get seachem trace in my country).

Here's a few links that describe boron toxicity - not aquarium stuff but still there are plants - no?

"Boron toxicity is a significant problem in horticulture. In some regions 
of the US, B toxicity is the primary determinant of species survival. To manage 
B toxicity requires the ability to identify the symptoms of B toxicity. Whereas 
the "classic" symptoms of B toxicity (marginal burn of oldest leaves) are 
familiar to most horticulturists, these symptoms do not occur in all species. 
Recently, we have demonstrated that a large number of extremely important 
horticultural species show none of the characteristic symptoms of B toxicity as 
a result of the high degree of B mobility in these species. As a consequence, B 
toxicity cannot be reliably diagnosed in these species and hence B cannot be 
adequately managed"

http://ucce.ucdavis.edu/datastore/detailreport.cfm?usernumber=6&surveynumber=232

"Symptoms of B toxicity are first seen in older leaves. They include yellowing between the veins (left) followed by necrosis"

http://www.agric.nsw.gov.au/reader/horticulture-greenhouse/7513 
" 
Early symptoms of boron toxicity include a yellow-green interveinal chlorosis developing first on the older leaves and spreading progressively to the younger leaves (Photos 7a and 7b). It is also usual to find the affected leaves cupped either upwards (Photo 7b) or downwards (Photo 7c).

As the toxicity becomes more pronounced, the interveinal chlorosis quickly gives way to small patches of brown necrotic tissue which develop between the minor veins and extend to the midrib (Photos 7c and 7d). Necrosis of the leaf margins is also common (Photo 7d).

Eventually, necrotic patches link up forming a continuous zone of dead tissue between the major veins. As this necrotic tissue weathers, it changes from brown to a silvery-grey colour (Photo 7e). By this stage the necrotic tissue has become very brittle and may break away giving a ragged appearance to the leaf (Photo 7f). "

http://www.hortnet.co.nz/publications/guides/kn/kiwitb.htm

Also regarding Iron - in order not to exceed the 1 ppm - if I dose ferrous gluconate then I shouldn't exceed 0.125 ppm iron. That means I have to choose... - either macrandra or Discus. Probably none of the folks dosing 0.2-0.3 ppm keep sensitive fish. Or am I wrong - anyone?

Aviel.


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## Laith (Sep 4, 2004)

I haven't heard of Discus being sensitive to iron levels above 0.1...

I have Discus and my iron levels vary from 0.15 to 0.2 and I've never had a problem.

Where have you heard about this?


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## MOR B. (Oct 9, 2003)

aviel, u can get seachem trace at asea's in holon. + i think u should call the municipal clerk at ur city and check what is the level of all the metals, nitrates etc. before u make a compration between u and other people dosage in different countries. i called givataim water department and they gave me all the info i needed. + why buy seachem if u have good results with csm? u can always use less. do u us borric acid ? how much? what do u have n your substrate (upper n lower layers)?


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