# [Wet Thumb Forum]-Fertilizer preservatives



## Mortadelo (Mar 14, 2004)

Which preservatives do commercial brands use in their products to preserve fertilizers?. I am looking for an alternative to storage in the fridge.

Thanks!.


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## Mortadelo (Mar 14, 2004)

Which preservatives do commercial brands use in their products to preserve fertilizers?. I am looking for an alternative to storage in the fridge.

Thanks!.


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## António Vitor1 (Feb 2, 2003)

Caution I am not an expert on this (someone correct me if I am wrong on some statments)...

The only thing in the fertilizer that could happen is some precipitation or chelate degradation.

Precipitation is not a problem (I do not know if at lower temperatures that could happen ), but chelator degradation (EDTA DTPA,etc...) might be a problem.

EDTA is stable bellow pH 6, so if we put some HCL to put the pH of the fertilizer bellow 6 is good.

Of course there are lots of chelators, and some are stable at higher pH, for example DTPA, DTPA doesn't require such those pH levels, but I think they last more if pH is bellow 6.

the most harmfull to the life of all fertilizer is light!
light can degrade easily most of the chelators used (mostly EDTA, and EDTA)

SO instead of putting it on the fridge, it's better to put the fertilizer in the dark room at normal temperature (normal house temperatures).

fertilizer preservatives used:

some use citric acid to lower the pH (I think that citric acid is a organic/natural chelator), others use sulphuric acid, or HCL.

(I do not know of any fertilizer with sorbic acid)

I am a man of PMDD (recipe close to TMG), the fisrt time i mixed the components I used aceptic acid (vinager) to lower the pH bellow 6, in that time I used tap water. Now, I only use destilated water, some of the acids used in my PMDD (boric acid) are enough for reaching aceptable levels of pH, so I quit dosing vinager into the mix...

It doesn't last forever but that is good enough for me. My mix only last for 2 months, total degradation take much longer.

I don't think that citric acid/vinager are good, they will increase organic matter on the water...

Regards!
AntÃ³nio Vitor

[This message was edited by AntÃ³nio Vitor on Mon March 17 2003 at 04:40 PM.]


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## MarcinB (Apr 16, 2004)

I add some HCl to my DIY TMG, to bring the pH down to 4,0. Low pH value inhibits the microbial growth in the fertilizer (some kind of fungus IMO). I store it in the fridge. It's not crucial, but IMO it helps a bit, especially during the summer.


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## António Vitor1 (Feb 2, 2003)

with destilated water my fertilizer pH is in 4-5 range, without HCl

Hcl doesn't do any harm, I guess...

I never had fungus, don't know if there are any bacterias able to survive on my fertilzer mix.

I think that chelator degradation is much more important in the fertilizer life than a little fungus, of course if there isn't any fungus, then the pH is low enough for good EDTA/DTPA/.. life.

low temperatures improve the fertilzer life?

I have a TMG bottle here and it says:
*min temp 5Âºc*

why this minimum temperature?

there is two possible answers (I am not sure what is the right one)

1- ICE crystals might destroy those molecular compounds (chelators)...

2- ICE might destroy the botlle (ice occupies more volume than liquid water)

there is nothing about maximum temperature...
so I guess low temperatures might do more harm than higher ones...

[This message was edited by AntÃ³nio Vitor on Mon March 17 2003 at 08:57 PM.]


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## Mortadelo (Mar 14, 2004)

I make separate solutions for everything. 
KNO3, KH2PO4 and my trace mix (EDTA) develop some kind of mold or fungus. My K2SO4 solution does, but very little. I use tap water. I use all of them without problems so far.

My tracemix is in the fridge, that is suppoused to expand its shelf life, chelates are organic molecules, they decompose over time. Cold, darkness and an acidic pH benefits them.

I was wondering why commercial fertilizers are crystal clear for months and I get this mold in a couple weeks.

Regards.


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## António Vitor1 (Feb 2, 2003)

test your fertilizer mix for pH. it should be around 4 pH...
in that acdity there are few fungus or bacterias that can survive...

To improve fertilizer life (or only for some colour), TMG has some E123, I think this is a cancerigenous element, (not sure about this)

additives out

E123 gives a red/brown colour to the TMG mix, otherwise it would look like water...(less sales)









if you do this there is no need for any fridge.

[This message was edited by AntÃ³nio Vitor on Tue March 18 2003 at 02:58 PM.]


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