# Dissolving  methylparaben/nipagin



## oviparous (9 Jul 2015)

Hello all,

I want to use Methyl 4-hydroxybenzoate as a preservative in my macro and micro mix. The recommendation is 1gr/l. 
But i find very little info on how to dissolve it. It has to be dissolved in ethanol because that is the only way it will dissolve and become active, as i read. But i can't find how much ethanol is needed  to dissolve 1gram.
Anyone?


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## alto (9 Jul 2015)

Reference - just scroll down for the *Solubility*


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## zozo (9 Jul 2015)

But it also has antifungal properties, so be sure it's safe to use for aquatic life forms.. Like antifungal in kit is a nono..


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## oviparous (9 Jul 2015)

Thanks!

There are commercial fertilizers like Drak that use it in their mixture, and it is considered biodegradable and safe. 
Hope the fish don't get drunk from the ethanol.


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## zozo (9 Jul 2015)

few months back i had a fluke infection.. Used Praziquantel from Dr. Bayer. this is also dissolved in ethanol, i noticed after the second dose that the green algea like it they got brighter in color and started blooming. So rather go easy on the alcohol.. I don't know the mix ratio of that bayer prazi stufff.  But it contaisn ethanol.


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## alto (10 Jul 2015)

Solubility in ethanol is 52g mp in 100 g ethanol (which has a density of 0.789g/ml at 20C, so 100g X 1ml/0.789g ~ 127ml), so assuming you have the "dry powder" & a decent scale, measure 
41g methylparaben  & add 100 ml ethanol - this will be close to the point of saturation, so add another 100 ml ethanol for an "easier" working solution, which now contains 0.2 g mp/ml, so you want to add 5ml to your 1litre of fertilizer mix.

If you have a premeasured 1g amount of mp (not many home scales are meant to accurately measure these amounts), then just dissolve in 5 ml ethanol (again this should give you "easy" solubility) etc


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## oviparous (10 Jul 2015)

Thanks Alto!

I dissolved 25gr. in 100ml ethanol 96%.
So now I've got about 115ml solution, going to measure it accurately tomorrow.
115 : 25 = 4,6  So 1gram in 4,6ml.


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