# Does a 2 stage filter remove needeed chemicals?



## n87 (3/3/17)

Hi All,
I have searched AHB and google, and am unable to get a straight answer, so im putting it out to the people who hopefully know off the top of their head.
I have filtered my water for the last handful of batches, but I am starting to look further into water chemistry for my mash.

I run a 2 stage filter,
1um sediment
0.5um carbon block.

Both 'silverised' to kill things, I mainly got this to help stop them going mouldy between brews as opposed to killing anything for the mash.
the water gets trickled through, no real measurement, but it takes in the general vicinity of an hour to get the ~60L mash volume (usually doing things so don't take note of the time), which would make it ~1L/m.


My water (report from council) mg/L, average

TDS 145
CaCo3 51
pH 7.5

Ca 23
Chloride 40
Cl (total) 0.93
Fluoride 0.88
Mg 3.7
Sulfate 32
Na 29

I think i got everything usefull, let me know if you need something else.

So is the filter likely to remove any of the goodness from my water? if so, what?

Thanks


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## manticle (3/3/17)

My understanding is that inorganic salts/minerals will remain if using carbon filter. Stuff like chlorine will get removed.


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## Lyrebird_Cycles (3/3/17)

It's all about surface energy.

The surface area of the carbon is huge and hydrophobic: anything which loses energy by adhering to the carbon will do so. This is called adsorption and will affect things which are only loosely bound in the fluid like organics. As I understand it chlorine removal is also via adsorption.

Things which are tightly bound, like ionic solutes (salts), would have to gain a lot of energy to come out of solution and bind to the surface, so they don't.


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## n87 (3/3/17)

Thanks guys, that makes things easier


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