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Old 03-09-2012, 04:16 PM   #11
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I'm leaving South Texas in just over a week (sob!) and will be home around Monday the 19th. I'd like to brew almost right away, since I'm very low on homebrew!

I only have my wee netbook here, so I was wondering if some helpful (and smart) soul could help me guestimate the slaked lime and calcium chloride I'd need to drop the alkalinity. I can't get to Kai's or Martin's spreadsheet from this goofy netbook.

My water is:
calcium 57
magnesium 26
sodium 9
chloride 14
sulfate 45
bicarb 228

I'm not sure of the recipe exactly, but it'd be a 10 gallon batch of an IPA. Probably 20 pounds-ish of two row, and 2 pounds cara/crystal malts. (I can only fit 23 pounds in my MLT). Using 1.25 quarts per pound, strike water would be 27.5 quarts. I'd sparge with about 8 gallons of water.

Can anybody who has excess time and the inclination run that? I know I'd have to add some calcium chloride (or CaS04) to the lime to drop the alkalinity. If anybody can help me calculate this in advance of brew day, I'd really appreciate it!

I'm ordering the aquarium alkalinity test set and the slaked lime online to have it when I get home.

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Old 03-09-2012, 04:44 PM   #12
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Originally Posted by Yooper View Post
I'm leaving South Texas in just over a week (sob!) and will be home around Monday the 19th. I'd like to brew almost right away, since I'm very low on homebrew!

I only have my wee netbook here, so I was wondering if some helpful (and smart) soul could help me guestimate the slaked lime and calcium chloride I'd need to drop the alkalinity. I can't get to Kai's or Martin's spreadsheet from this goofy netbook.

My water is:
calcium 57
magnesium 26
sodium 9
chloride 14
sulfate 45
bicarb 228

I'm not sure of the recipe exactly, but it'd be a 10 gallon batch of an IPA. Probably 20 pounds-ish of two row, and 2 pounds cara/crystal malts. (I can only fit 23 pounds in my MLT). Using 1.25 quarts per pound, strike water would be 27.5 quarts. I'd sparge with about 8 gallons of water.

Can anybody who has excess time and the inclination run that? I know I'd have to add some calcium chloride (or CaS04) to the lime to drop the alkalinity. If anybody can help me calculate this in advance of brew day, I'd really appreciate it!

I'm ordering the aquarium alkalinity test set and the slaked lime online to have it when I get home.
Hopefully AJ or Martin can correct me if I'm wrong on this. Your alkalinity is about 188 mg/l as CaCO3 I'd guess. Your calcium hardness as CaCO3 is about 54*2.5, or 135. So, you need another 188-135, or 53, mg/l as CaCO3. This is about 21.2 Calcium as the ion. You'll also need another ~75 mg/l calcium as CaCO3 to end up with 50 mg/l calcium, assuming you drop your alkalinity to 50 mg/l as CaCO3, since the calcium drops the same amount (roughly) as the alkalinity. With gypsum as an example, this would be about .8 grams/gallon. This would put your total sulfate to about 200 ppm, though, so you may want to sub some calcium chloride (probably fine for an IPA though). The amount of slaked lime I normally add, which gets me down to ~50 mg/l alkalinity (aquarium test kit), is (.74*alkalinity / 1000 * 3.785) grams / gallon. In your case, that's about .526 grams / gallon. You'll want to treat something like 15.5 or 16 gallons of water (so you have room to rack off the water). So, 16 *.526 = 8.416 grams of lime. Your gypsum would be about .8 * 16, or 12.8 grams.

EDIT: Oops, you said calcium chloride.
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Old 03-09-2012, 04:49 PM   #13
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Deleted post: Off Topic, not lime treatment

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Old 03-09-2012, 05:55 PM   #14
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Quote:
Originally Posted by Yooper View Post
I'm leaving South Texas in just over a week (sob!) and will be home around Monday the 19th. I'd like to brew almost right away, since I'm very low on homebrew!

I only have my wee netbook here, so I was wondering if some helpful (and smart) soul could help me guestimate the slaked lime and calcium chloride I'd need to drop the alkalinity. I can't get to Kai's or Martin's spreadsheet from this goofy netbook.

My water is:
calcium 57
magnesium 26
sodium 9
chloride 14
sulfate 45
bicarb 228

I'm not sure of the recipe exactly, but it'd be a 10 gallon batch of an IPA. Probably 20 pounds-ish of two row, and 2 pounds cara/crystal malts. (I can only fit 23 pounds in my MLT). Using 1.25 quarts per pound, strike water would be 27.5 quarts. I'd sparge with about 8 gallons of water.

Can anybody who has excess time and the inclination run that? I know I'd have to add some calcium chloride (or CaS04) to the lime to drop the alkalinity. If anybody can help me calculate this in advance of brew day, I'd really appreciate it!

I'm ordering the aquarium alkalinity test set and the slaked lime online to have it when I get home.
Assuming a water pH of 7 you would have alkalinity (it would be so much better if people would report alkalinity and pH rather than bicarbonate) of 189 and a total carbo content of 4.6 mmol/L. 19.4% of that or 0.89 mol is carbonic. The rest, 0.805*4.6 = 3.7 mmol is bicarbonate. The first thing that needs to be done is conversion of the carbonic to bicarbonate:
2H2CO3 + Ca(OH)2 --> Ca++ + 2H2O + 2HCO3-
thus 1 mmol of lime is required for each 2 mol of carbonic and we would need 0.89/2 = 0.445 mmol of lime per liter for this purpose. Having converted all the carbonic to bicarbonate we'd have about 4.6 mmol of bicarbonate to dispose of and realistically expect we might get rid of 3.6. The reaction here is
Ca++ + 2HCO3- + Ca(OH)2 --> 2CaCO3 + 2H2O

Thus, again, 1 mmol of lime takes out 2mmol of bicarbonate (and 1 mmol of Ca++). For the 3.6 mmol/L we would, thus, require 1.8 mmol of lime. The total lime requirement would then be 0.445 + 1.800 = 2.245 mmol/L. Multiplying that by 74, the molecular wt of Ca(OH)2 gives 166 mg/L or 628 mg/gal. You would take out 2.245 mmol of calcium per liter (89.8 mg) but you only have 57 so you would need to add at least 32 mg/L just to have enough for the alkalinity reduction. As you will doubtless want more than that to, say, the extent of 30 mg/L residual you would have to add 30 mg/L additional for a total of 62 mg/L i.e. 1.5 mmol of CaCl2 (1.5*147 = 220 mg/L) or CaSO4.2H2O (258 mg/L).

De Clerck recommends preparation of 3 doses of lime. One at 0.9*166 mg/L, one at 166 mg/L and one at 1.1*166 mg/L. Three liters would then be softened and the dose that worked best would be scaled up for the whole volume.

As I expect you'll want to go after some of that magnesium add the entire calculated dose to 1/3 the water. That should drop 1/3 the magnesium. Decant off that and then add the remaining 2/3 of the water. Your final pH should be in the eights.
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Old 03-09-2012, 06:15 PM   #15
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Assuming a water pH of 7 you would have alkalinity (it would be so much better if people would report alkalinity and pH rather than bicarbonate) of 189 and a total carbo content of 4.6 mmol/L. 19.4% of that or 0.89 mol is carbonic. The rest, 0.805*4.6 = 3.7 mmol is bicarbonate. The first thing that needs to be done is conversion of the carbonic to bicarbonate:
2H2CO3 + Ca(OH)2 --> Ca++ + 2H2O + 2HCO3-
thus 1 mmol of lime is required for each 2 mol of carbonic and we would need 0.89/2 = 0.445 mmol of lime per liter for this purpose. Having converted all the carbonic to bicarbonate we'd have about 4.6 mmol of bicarbonate to dispose of and realistically expect we might get rid of 3.6. The reaction here is
Ca++ + 2HCO3- + Ca(OH)2 --> 2CaCO3 + 2H2O

Thus, again, 1 mmol of lime takes out 2mmol of bicarbonate (and 1 mmol of Ca++). For the 3.6 mmol/L we would, thus, require 1.8 mmol of lime. The total lime requirement would then be 0.445 + 1.800 = 2.245 mmol/L. Multiplying that by 74, the molecular wt of Ca(OH)2 gives 166 mg/L or 628 mg/gal. You would take out 2.245 mmol of calcium per liter (89.8 mg) but you only have 57 so you would need to add at least 32 mg/L just to have enough for the alkalinity reduction. As you will doubtless want more than that to, say, the extent of 30 mg/L residual you would have to add 30 mg/L additional for a total of 62 mg/L i.e. 1.5 mmol of CaCl2 (1.5*147 = 220 mg/L) or CaSO4.2H2O (258 mg/L).

De Clerck recommends preparation of 3 doses of lime. One at 0.9*166 mg/L, one at 166 mg/L and one at 1.1*166 mg/L. Three liters would then be softened and the dose that worked best would be scaled up for the whole volume.

As I expect you'll want to go after some of that magnesium add the entire calculated dose to 1/3 the water. That should drop 1/3 the magnesium. Decant off that and then add the remaining 2/3 of the water. Your final pH should be in the eights.
Well, I was close with my predicted amount of lime. Mine is about .85 x your amount. However, when I went with the amount you are proposing for my water (proportionally) I seemed to have extra lime left over. Perhaps my bicarb isn't quite as high as my report says?

EDIT: My number is closer to 90% of yours if I use 189 alkalinity.
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Old 03-09-2012, 06:55 PM   #16
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That makes sense! Thank you so much.

I was simply diluting my tap water 30-50% RO for most beers, but the last couple had a bit of harshness to them. I suspect that the RO "machine" at the store hasn't been maintained and I'm hesitant to try it again. We live in a small town, and that's the only one around. I can't really justify my own RO system, so I thought the slaked lime would be just the ticket- using my own good tap water (just high in alkalinity)- if it's as easy as it seems.
If I brewed as much as you do, I'd certainly think about buying an RO system. Having to mess with the water like that has got to be a serious amount of time and effort.

I'm thinking about it and I only brew once a month, on average.
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Old 03-09-2012, 07:59 PM   #17
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If I brewed as much as you do, I'd certainly think about buying an RO system. Having to mess with the water like that has got to be a serious amount of time and effort.

I'm thinking about it and I only brew once a month, on average.
Yes, I'm kicking around the idea.

My pH was 8.2 in Ward's testing, but recently it was more like the high 7's when I tested it at home with my new pH meter. My alkalinity (Hco3) was 208, I believe. I don't know if that changes AJ's figures.

I'm going to have to read and reread and reread again AJ's post, as I don't quite get it yet.
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Old 03-09-2012, 08:22 PM   #18
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Yes, I'm kicking around the idea.

My pH was 8.2 in Ward's testing, but recently it was more like the high 7's when I tested it at home with my new pH meter. My alkalinity (Hco3) was 208, I believe. I don't know if that changes AJ's figures.

I'm going to have to read and reread and reread again AJ's post, as I don't quite get it yet.
If the alkalinity actually is higher then you'll need more lime and more calcium.
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Old 03-10-2012, 09:53 PM   #19
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If the alkalinity actually is higher then you'll need more lime and more calcium.
I don't really want someone to do the work for me (alright, yes I do ) but without "seeing" it I'm having trouble understanding where to start.

I understand about doing the 1/3 of the water first (as described by ajdelange) but I'm not sure where to start with the amount of lime and the amount of CaCl2.
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Old 03-10-2012, 09:59 PM   #20
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I lime-soften my water. I didn't find the calculators super helpful in predicting how much lime I'd need, but I think that's operator error, and nothing wrong with the calculators. I mostly just follow Martin's and AJ's general instructions and just add lime a bit at a time (1tbsp at a time for about 25 gallons of until I hit my target pH. I've found 11.5 to be the minimum to get any decent precipitation, and around 12 precipitates out pretty well. I let the hardness precipitate out overnight, then adjust the water pH with acid down to 8, then check my GH/KH at that point.

It works pretty well. The GH/KH test results are always within 1*dH on each batch, which is pretty consistent given that I don't measure how much lime I add. After you do it a few times you'll get a feel for how much lime you need to add based on how the water looks.

So I guess I'm saying don't get too bogged down in the math, because it's pretty straightforward.

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