Reducing alkalinity with slaked lime

[Yooper]

Back in #14 I calculated 220 mg/L CaCl2 per liter of water treated. Note no water of hydration specified in that - assume your product is about 80% CaCl2 by weight).


The calculation in #14 was based on a calcium residual of 30 mg/L assuming that the bicarbonate was reduced to an alkalinity of 50. The chloride calculates out to 119 mg/L. All these are very iffy. You will really need to experiment.

Thank you! I have to read these things over and over to "get it". I appreciate your help so much!

 

[afr0byte]

Huh, I just did another test treatment of ~1.5 gallons. It was only about half an hour ago that I did the treatment. It's already precipitated quite a bit of, presumably, chaulk. I tested the pH and it'd already gone down to about 7.3. That pH reading of 7.3 seems kind of odd to me, since that's what the water pH reading had been when I started the treatment. Perhaps I didn't mixing in the top up water well enough? I had treated 1 gallon, mixed, and then added another ~.5 gallons.

EDIT: I used my kH kit and got 2 or 3 dH (definitely 3 was yellow, but 2 seemed yellow too).

 

[Nateo]

Yooper: For your water I'd probably go AJ's route, and only treat part of the water.

The reason I treat the whole amount of water is that I have really high magnesium levels in my well water, and about twice as much bicarbonate. Treating the whole amount up to 12 gets rid of most of the Mg.

It takes a bit of practice, but by the third batch you should have a feel for it.

 

[afr0byte]

I treated some water (way more than I needed, but the measurement error was less of a factor with the larger volume) yesterday to do a sample mash for this coming weekend's brew session. I figured I'd post a picture of the bottom of the treatment vessel (the largest non-brewing-pot that we have). The measured alkalinity was ~53 ppm as CaCO3. The measured calcium (aquarium calcium test kit) ended up being in the 60-80 ppm range.

 

[Nateo]

I use a 32g Rubbermaid trashcan for my lime softening. The gray and white ones are food grade. The gray ones are easy to find in hardware stores. I've found I need to treat about 20-25% more water than I plan on needing. 25 gallons is a good amount for a 10 gallon batch.

 

[afr0byte]

I use a 32g Rubbermaid trashcan for my lime softening. The gray and white ones are food grade. The gray ones are easy to find in hardware stores. I've found I need to treat about 20-25% more water than I plan on needing. 25 gallons is a good amount for a 10 gallon batch.

Huh, thanks for the tip. I normally use my extra 10 gallon pot (I do 5 gallon batches). But, with bigger beers I may need more than the 9ish gallons I've gotten post treatment. Plus, we need to buy some garbage cans to store our trash in the garage (we saw a mouse the other day), so I'll be buying some anyways.

 

[Yooper]

I use a 32g Rubbermaid trashcan for my lime softening. The gray and white ones are food grade. The gray ones are easy to find in hardware stores. I've found I need to treat about 20-25% more water than I plan on needing. 25 gallons is a good amount for a 10 gallon batch.

That's a great idea! I don't seem to have any big enough vessels that I want to devote to this.

A couple of questions, then. How do you decant? Do you pump? I'm trying to visualize this.

I assume I could treat 1/3 of the water (as per AJ's instructions) to reduce magnesium, decant to the larger vessel and then leave it sit overnight. Does that seem doable?

 

[Nateo]

Yooper - I have maybe 4 feet of silicone tubing I use for my pump. I place the trash can on a stool (before filling it), then use the tube as a siphon, and place a few buckets on the floor by it to fill. After I siphon off all as much as I can, I swirl up the precipitate still in the can, then dump that in a pot to save for next time. I'll rinse the can, then dump the water I decanted back into the empty can. I'm working on a bulkhead for it, like on a bottling bucket, so I don't have to mess with the silicone tubing anymore.

You could definitely treat part of the water in a smaller bucket, then dump it in the can to treat the rest of the water.

 

[Yooper]

Yooper - I have maybe 4 feet of silicone tubing I use for my pump. I place the trash can on a stool (before filling it), then use the tube as a siphon, and place a few buckets on the floor by it to fill. After I siphon off all as much as I can, I swirl up the precipitate still in the can, then dump that in a pot to save for next time. I'll rinse the can, then dump the water I decanted back into the empty can. I'm working on a bulkhead for it, like on a bottling bucket, so I don't have to mess with the silicone tubing anymore.

You could definitely treat part of the water in a smaller bucket, then dump it in the can to treat the rest of the water.

Thanks! My next batch should be on Wednesday or Thursday (assuming my lime and aquarium test kit come today) and I need about 13 gallons of water for my 8.25 gallon batch. Lifting 13 gallons of water bucket by bucket will doable, but not fun. I wonder if in the future, I could do the water treatment on my brew stand (where the MLT goes) and use the pump to decant. I'd have to add fittings to whatever vessel I decide on, but that sure seems easier than siphoning/pouring. I wonder if I could do it without disturbing the precipitate, though.

Or...............decant via gravity to my MLT on a stool with the treatment vessel on the stand. Then simply pump from my MLT to my HLT. I think that would work!

 

[Nateo]

Lifting 13 gallons of water bucket by bucket will doable, but not fun.

You're right. I'm planning on getting another can, and building a stand for it, so I can use a valve to dump water from the higher can into the lower can, then having a valve on the lower one I can hook my pump to, and pumping the finished water into my HLT.

 

[Yooper]

The real beauty of Hubert's method is that you don't have to calculate or weigh out anything. Just add lime, gradually, to 1/3 of the water until pH reaches 11+ (but don't go too far). Add some chalk before adding the lime and stir well to get it in suspension and keep it there as you add the lime. Also add any supplemental calcium salts.The chalk doesn't do anything but serve as precipitation sites for the chalk which is to precipitate. Let it sit and settle and then decant.

Now add some more chalk to the decanted water, stir and start to add untreated tap water. Stir and monitor the pH. When the pH gets to around 8.5 you are finished. The bicarbonate in the added untreated water is neutralizing the excess OH- from the extra lime you added to get to pH 11+

Ca++(from water) +2HCO3- + Ca++(from lime) +2(OH-) ---> CaCO3 + H2O
As the reaction takes place OH- is consumed and you can see the pH drop. This neutralization of the OH- is very important. At pH 11 the OH- contributes alkalinity of 50 ppm as CaCO3. At pH 10 it contributes 5 and at pH 9 only 0.5 so once the pH has pulled back below 9 you should be OK.

Or the other thing you can do without measuring chemicals is add lime (plus chalk and extra calcium) until pH 11+ is reached, allow time for precipitation, decant and then bubble air through for a few days or until the pH falls back to the pH you want. This is better than neutralizing with another acid in the sense that you don't get any of the anion of the other acid.

I just followed these directions for the first time.

I don't have any vessels handy larger than 10 gallons, so I thought I'd treat 10 gallons at a time, and brew on Wednesday or Thursday.

I used the above info and Kai's spreadsheet, and found that I could use 2 grams gypsum and 4 grams calcium chloride to get my calcium up and I used a pinch of chalk. I stirred well, and had it at 66 degrees.

I saw that Kai's spreadsheet called for 52.6 grams of lime so I weighed that out, but only planned to use as much as I needed according to the above directions.

I had 3.30 gallons of water and after the first lime addition the pH shot up. I added a bit more, but by then the pH was 12.8! I stopped, since I was WAY over 11+. I measured what was left and found that I used a total of 37 grams of lime.

I'm letting it sit now, and will decant later.

Then I see that I will add untreated tap water until my pH gets to around 8.5.

Aside from not liking lifting all that water, it seems easy enough. At least at this point! My aquarium test kit didn't come today, so I will test tomorrow when it does come for the GH and KH.

 

[Yooper]

Oh, I have another question for any body who can help! When I did the treatment of 1/3 of the water first, it was to drop magnesium.

I assume this happens quickly? And then approximately how much does it drop? If that's been answered already, I do apologize. My brain is pretty full right now.

 

[Nateo]

I assume this happens quickly? And then approximately how much does it drop? If that's been answered already, I do apologize. My brain is pretty full right now.

I believe if you raise the pH over 12 you'll drop nearly all of the Mg in that portion. It takes about 8-12 hours for my water to drop clear after treatment.

 

[ajdelange]

The reaction is fast but the settling time may be appreciable. That's one of the advantages of adding the chalk. The magensium hydroxide is a gel which will entrap some of the chalk you added as nucelation sites and the calcium carbonate which is also precipitated in thiis phase (of treatment) and you should see a layer at the bottom after some time.

 

[Yooper]

Thank you both!

When this is finished, and I want to guess my final results, the majority of the Mg will be gone out of this 3.3 gallons, and the other 6.6 gallons will not drop since it's added later (but the alkalinity WILL drop) I should expect that the total Mg in all water (which is 26 ppm out of the tap) would be about 17 ppm.

The aquarium kit did come, so I can measure the GH and KH when finished.

I'm assuming that this is almost necessarily a two-day process. Doing 1/3 of the water to drop the Mg, and waiting, and then doing the rest of the water, and waiting, means that in all practicality that it would have to be over a couple of days. I think I can do two 10 gallon "batches" at the same time, to have enough water for a 10 gallon batch until I find/figure out a bigger vessel.

 

[Yooper]

I had some issues (leaking ball valve) so I ended up starting over.

but now I really need some advice!

I started with 3.5 gallons of my tap water, stirred in a pinch of chalk and 2 grams CaS04 and 4 grams CaCl2. I started stirring in the lime, but by the time I stopped at only 30 grams, the pH was 12.7!

The precipitates dropped out right away, but I waited for it to settle. I racked off, and started stirring in my tap water, following the instructions to do so until my pH read 8.5. I was planning on a total of 10 gallons.

I must have really screwed up, because I have 25 gallons of water at 8.5, but I still have about 9 gallons in the first vessel that has a pH of 9 and I don't have any more buckets to dilute further!

I guess my questions are: did this happen because of the pH being too high at 12.7? I assume it did, but according to calculations on Kai's spreadsheet, I'd need like 57 grams of lime to drop the alkalinity (in 10 gallons) and I've only used 30 grams for 34 gallons of water.

My next question- now what? do I start over, keep diluting, stop?

 

[afr0byte]

I had some issues (leaking ball valve) so I ended up starting over.

but now I really need some advice!

I started with 3.5 gallons of my tap water, stirred in a pinch of chalk and 2 grams CaS04 and 4 grams CaCl2. I started stirring in the lime, but by the time I stopped at only 30 grams, the pH was 12.7!

The precipitates dropped out right away, but I waited for it to settle. I racked off, and started stirring in my tap water, following the instructions to do so until my pH read 8.5. I was planning on a total of 10 gallons.

I must have really screwed up, because I have 25 gallons of water at 8.5, but I still have about 9 gallons in the first vessel that has a pH of 9 and I don't have any more buckets to dilute further!

I guess my questions are: did this happen because of the pH being too high at 12.7? I assume it did, but according to calculations on Kai's spreadsheet, I'd need like 57 grams of lime to drop the alkalinity (in 10 gallons) and I've only used 30 grams for 34 gallons of water.

My next question- now what? do I start over, keep diluting, stop?

I usually only need about 6 or so grams for ~9 gallons of water. So, 30 grams is a lot! I'm guessing you have a number entered wrong in the spreadsheet.

 

[Yooper]

I usually only need about 6 or so grams for ~9 gallons of water. So, 30 grams is a lot! I'm guessing you have a number entered wrong in the spreadsheet.

So, use the water I have that is 8.5, after decanting?

 

[Nateo]

I've never tried the split method, so I can't really say. Did you check the hardness with your test kit? As long as your hardness and RA are where you want them to be, and you have as much water as you need, you'll be fine.

 

[pjj2ba]

I usually only need about 6 or so grams for ~9 gallons of water. So, 30 grams is a lot! I'm guessing you have a number entered wrong in the spreadsheet.

Seems like a lot to me as well. I'm using around 3-4 grams for 10 gal. Perhaps a decimal point error?


I use my boil pot sans pickup tube to do my water treating. After it settles I pump it over the my HLT and mash tun. There is about 1.5 gal that I cannot drain with the pump since I took the pickup off. Then I just slowly tip the pot and drain it into jugs being careful to leave the precipitate behind.

 

[Yooper]

I just did the GH/KH test on one of the buckets of water. Apparently I diluted too much or something because the KH was 161, while the GH was 196.9!

so I think I'm back to the drawing board.

I assume it's because I didn't add enough CaCl2 and CaSo4 for the amount of water I started with since I figured it for 10 gallons.

 

[Nateo]

I just did the GH/KH test on one of the buckets of water. Apparently I diluted too much or something because the KH was 161, while the GH was 196.9!

so I think I'm back to the drawing board.

Is that ppm? My test kit gives me German degrees. I usually end up with about 7* GH and 2-3* KH. I do use a bunch of lime in my way, but I think I mentioned that already.

 

[Yooper]

Is that ppm? My test kit gives me German degrees. I usually end up with about 7* GH and 2-3* KH. I do use a bunch of lime in my way, but I think I mentioned that already.

That's with the "conversion table" they give.

It was 9 kH and 11 Gh before the conversion.

I have one 10 gallon batch sitting there, with the pH just up over 9 since I couldn't add any more water but it really looks like I'm getting a lot of precipitation out of that one.

I think when I added more water to bring the pH down to 8.5 that I didn't have enough calcium to encourage more precipitation. I could run and add some to the buckets now, but I'm about ready to think I'm not smart enough to do this.

On the bright side, Bob saw me messing with water, my pH meter, chemicals, and said, "OK- that's it! We're going to look at RO systems". So there is a silver lining!

In the meantime, I have about 35 gallons of water sitting in my brewery, and I want to brew tomorrow. I might end up putting 14 gallons in my BK and boiling it to precipitate out the alkalinity at this point.

 

[Nateo]

You might want to try the way Martin recommended (that I use) at least once before you buy an RO system. I got to the same point you're at, and about gave up. The way I do it now requires very little calculating.

 

[Nateo]

I'm working on some recipes right now for my brew day tomorrow. I'll be up another half hour or so if you want me to help with your water tonight. It'll be tight, but you should have enough time to try my water treatment and still brew tomorrow.

 

[Yooper]

I'm working on some recipes right now for my brew day tomorrow. I'll be up another half hour or so if you want me to help with your water tonight. It'll be tight, but you should have enough time to try my water treatment and still brew tomorrow.

Well, sure, if you have time!

I have vessels of water all over the place with a pH of 8.5. I don't know if I can start there or not, but if you can give me your "Ten Steps for Morons", I'd be thrilled!

 

[Nateo]

So here's what I do, in only 6 steps:
1) Add lime until you hit 12. (like, a bunch of lime ~ several tbsp)
2) Let precipitate settle out (overnight usually)
3) Decant
4) Add phosphoric acid until pH drops under 8
5) Let precipitate settle out (apatite, looks like jelly)
6) Enjoy

That's the quick and dirty method I use, but I end up with reasonably soft water, and "some" amount of excess phosphate. Since malt contains a lot of phosphate, I don't worry too much about it.

You have to lower the pH and let the apatite precipitate off before you test it, otherwise there will still be way too much calcium left over from the large amount of lime. My GH is like 27* before it precipitates.

It takes a few hours for the apatite to precipitate, so I'd add the acid first thing in the morning. Sometimes I rush it a little too much, and end up using brewing water with a small amount of apatite still in suspension. I haven't noticed any ill-effects, but it's probably not ideal. It's probably better to wait until it drops clear.

When I add the acid (I use 10% phosphoric) it takes a few tbsp to get the pH to drop from 12 to 10, then only maybe 1 tsp to drop from 10 to 8. So if you add acid and it doesn't drop right away, don't go too crazy with it.

Let me know if you have any questions.

 

[Yooper]

Ok, so you decant twice?

I just went in and decided to give it another try. There was some precipitate in the buckets, but not really all that much. so I dumped those and used my two cooler MLTs, with 9 gallons in each one.

I added some CaCl2 and CaSo4 (a total of 4 grams CaSo4 and 8 grams CaCl2 because I'm low in calcium and my understanding is that I need the calcium to precipitate the alkalinity). I added about a TBS of lime, and stirred like crazy. The pH in one is 11.89 (close enough, I thought) and the pH in the other is right at 12. I see stuff already "forming" and falling out.

So, in the morning, I should decant, adjust down to 8, and then decant?

That is doable, but decanting means lifting, which I hate! But I promise to give it my best shot.

Edit- oh, and THANK YOU. I have an IQ of 172, believe it or not. But I feel like an imbecile with this stuff.

I hope I have enough phosphoric acid.

 

[Nateo]

I decant after step 2. The next morning I'll add acid, then after the apatite settles, I'll pump the water off the top, straight into my BK to heat for strike liquor. Just try to leave as much of the jelly behind as you can.

If the pH is over 11, that's enough to get the hardness to drop out, it just drops faster at 12 than 11, so I shoot a little high. Have you made cheese? If you add enough lime, it looks like milk does when it breaks. If you add a little too much acid and the pH drops below 8, that's OK too, as long your mash pH is correct.

My way would probably work better if I added calcium, but figuring out how much to add sounds like math, so I skip it, and just treat my water as-is. I'll add any flavor minerals during the boil. Any acid will work, you'll just end up with the ion the acid leaves behind after the H+ leaves. So lactic leaves lactate, sulfuric leaves sulfate, phosphoric leaves phosphate, etc. I'm sure a small amount of lactic would be OK, if necessary.

 

[Yooper]

Have you made cheese? If you add enough lime, it looks like milk does when it breaks.

Actually, YES- that's exactly what my water looked like just now! It was like milk, long before the clean break!

I get it, I think! I wondered about decanting twice but I can actually pump so that is helpful. I don't really have big enough vessels for more than about 9 gallons of water (and of course lose some to the precipitate) so it's still sort of a PITA.