# Chalk For Water Adjustments



## Sammus (21/3/10)

Howdy... Anyone know where I can get some calcium carbonate (chalk) in a hurry? I have a heap of blackboard chalk here, and I'm about to brew, and was intending on using it.

After an incredibly small amount of thought, I figured it would contain some kind of binding agent which is no good. Upon further reading, I find out that blackboard chalk is rarely made of CaCO3 anymore.... do they sell CaCO3 powder at any normal shops I could zap down and get some on a sunday arvo while my sparge water is heating?


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## A3k (21/3/10)

Hi Sammus,
Don't quote me on this, but i reckon you can get it from hardware shops used for adding to soils. But i could be wrong.
cheers
Al


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## Sammus (21/3/10)

Yeah that's what I ended up doing. Checkout some calcium supplement tablets, 1.5g x 120 tabs for $10, or 2.5kg of 80% CaCO3, 20% SiO2 for $6 from bunnings. Checked the MSDS and all for that particular brands mix and its safe etc. Looks a bit more like sand than white powder, but oh well, fingers crossed it turns out non-deadly


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## leiothrix (21/3/10)

Try a pet shop. Petstock on the princes hwy at albion park sells it in kg lots for horses. It's a very fine white powder like you'd expect.

I'm sure that livestock place on northcliff drive would have some too and would be closer to you.

Rob.


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## Tony M (21/3/10)

If you have a little fibreglass factory you can go to, they use heaps of calcium carbonate (as talc) for filler. They would probably give it to you


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## BjornJ (21/3/10)

Sammus,
go by Dave's Homebrew next time you drive by North Sydney, he sells it for $5.60.

https://daveshomebrew.com.au/index.php?opti...9&Itemid=99 

thanks
Bjorn


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## kevin_smevin (22/3/10)

BjornJ said:


> Sammus,
> go by Dave's Homebrew next time you drive by North Sydney, he sells it for $5.60.
> 
> https://daveshomebrew.com.au/index.php?opti...9&Itemid=99
> ...



Grain and grape sell it but its pretty much useless. Its solubility is 0.001g in 100ml of water so it really wont help. Use CaCl or CaSO4 for Ca additions and bi carb for CO3 additions. Try and keep your CO3 below 50ppm, below 25ppm for pale beers.


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## Sammus (22/3/10)

yum yum yum said:


> Grain and grape sell it but its pretty much useless. Its solubility is 0.001g in 100ml of water so it really wont help. Use CaCl or CaSO4 for Ca additions and bi carb for CO3 additions. Try and keep your CO3 below 50ppm, below 25ppm for pale beers.



In water yeah, but it dissolves fine in the mash, which is where you should add it  I've got really soft water and my mash pH is way too low for anything with a bit of colour. I needed calcium and more alkaline water, so CaCO3 was perfect for the role. I ended up using the garden lime, I dunno how comfortable I am using it, so I'll keep an eye out for some more pure stuff, tho not really in a hurry anymore.

On a side note, pre fermentation tastings where quite good  I'm doing the mild from BCS except am using a 18 month old pack of W.Yorkshire 1469 I had kicking around. Pitched into a 5L starter the other day. Mrmalty said I'd still have nowhere near enough yeast for the job, but in less than 12 hours its almost blowing it's top. I underestimated my efficiency yet again, and got 26L in 30L fermenter so headspace isn't really something I have in abundance. Just now I noticed it was sitting at 24, so I've chucked in a fridge at 19 hoping it will slow down a bit.

Salt additions were:
To mash:
0.6g MgSO4
3g CaCO3

To kettle:
1.6g NaCl
0.8g Gypsum
2.9g MgSO4
2g NaHCO3

lands me pretty close the london profile in beersmith. My local drinking water analysis hasnt been updated since 2007 though, so it's probably way off. I had to aim for something though, this is my first go at water chemistry adjustment.


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