Beginners Guide to Water Treatment (plus links to more advanced water treatment in post #1)

IN Colchester though i live in Braintree it is still hard water, I think i will try this?
1) In Colchester, we have fairly hard water which often contains high levels of chlorine, so I start by running 25ltrs of tap water into my boiler and adding a level teaspoon of Gypsum, before bringing it to the boil and allowing it to boil for around 30 minutes to drive off the chlorine and help to remove the limescale. If you live in a soft water area, you probably won't need to do this, but the layer of "scum on the water surface in the 4th picture below shows you why I have to do it....







The water is left to cool overnight water to encourage the dissolved limescale (Calcium Carbonate) to drop out of solution. These two trial jars contain the treated water on the right and the sediment filled dregs on the left...

The following morning, the cleared water is run off, leaving the sediment behind. As I am brewing a bitter in this process, a teaspoon of Epsom Salts (Magnesium Sulphate) is now added to the brewing water, or liquor as brewers call it, to increase the pH level to that needed to

I put this up again as nobody commented

Does this make sense - it is info from my water company

Alkalinity is reported as mg/l as CaCO3 (calcium carbonate).



The value for your area is 242mg/l as CaCO3.



If you want the hardness value as HCO3-, then multiply by 1.22, which would give you a value of 295.24mg/l as HCO3-

OK understood, but what do do about Essex hard water if you need soft or just brew beers that do not mind hard water? Also LIDL Clarity Springs water is
ph 7.8 at source.
38mg/l clacium,
Mag 12 mg
potassium 2.5mg
Sodium 8 mg
Bicarbonate 135 mg
Chloride 12 mg
Suplpahte 14 mg
Nitrate 5mg
Dry residue at 180 degs c 219 mg
Is that alright for all brews? but use hard tap water for stouts and porters/

What about mild please?

Sorry as a newbie this is long way up my learning curve

bobukbrewer said:

I put this up again as nobody commented

Does this make sense - it is info from my water company

Alkalinity is reported as mg/l as CaCO3 (calcium carbonate).



The value for your area is 242mg/l as CaCO3.



If you want the hardness value as HCO3-, then multiply by 1.22, which would give you a value of 295.24mg/l as HCO3-

Click to expand...

Sorry I missed your post. Alkalinity as CaCO3 is the value you want, so use 242 ppm to work out your adjustments as per the OP.

Justin Dean said:

OK understood, but what do do about Essex hard water if you need soft or just brew beers that do not mind hard water? Also LIDL Clarity Springs water is
ph 7.8 at source.
38mg/l clacium,
Mag 12 mg
potassium 2.5mg
Sodium 8 mg
Bicarbonate 135 mg
Chloride 12 mg
Suplpahte 14 mg
Nitrate 5mg
Dry residue at 180 degs c 219 mg
Is that alright for all brews? but use hard tap water for stouts and porters/

What about mild please?

Sorry as a newbie this is long way up my learning curve

Click to expand...

First of all forget about water hardness, it's not the same as alkalinity which is the parameter we want to manipulate. Hardness tells you how much calcium and magnesium is in the water, both of which are good, whereas alkalinity tells you the buffering ability, ie the acid neutralising ability of the water.

Typically we want low alkalinity so that the mash pH will fall to the correct range, if the alkalinity is too high the grist won't be able to lower the pH enough. Darker grains and crystal malts are more acidic, meaning that you can get away with higher alkalinity water.

You can work out alkalinity as CaCO3 by dividing the bicarbonate value by 1.22. Once you have that value you can then adjust as necessary depending on the style.

Thank you for the advice so for Lidl Clarity Springs bicarboinate is 135 mg per litre therefor divide by 1.22 is 110.65, what does that mean, good or Is that the key figure to use in the calculator then adjust to suit the beer you are making? i thought ph reflected acidity and alkalinity and you want ph of about 6.5 mostly. Lidl clarity springs is ph 7.8 at source but according to my aquarium test strips it is 7 in the bottle, which is close enough.....

Justin Dean said:

Thank you for the advice so for Lidl Clarity Springs bicarboinate is 135 mg per litre therefor divide by 1.22 is 110.65, what does that mean, good or Is that the key figure to use in the calculator then adjust to suit the beer you are making? i thought ph reflected acidity and alkalinity and you want ph of about 6.5 mostly. Lidl clarity springs is ph 7.8 at source but according to my aquarium test strips it is 7 in the bottle, which is close enough.....

Click to expand...

OK so the target alkalinity is dependent on the beer colour (sort of, it's a lot more complex than that but it's not a bad rule of thumb):
For a pale beer - 20 ppm
For an amber beer - 35 ppm
For a brown beer - 75 ppm
For a black beer - 120 ppm

So that water from Lidl has an appropriate level of alkalinity for a stout or porter, however it's rather low in calcium which should probably be around 100 ppm.

The pH of the water is pretty much irrelevant because it has next to no impact on the pH of the mash, so you can ignore that. I think some of the misunderstanding of alkalinity comes from confusing it with basicity which is dependent on the pH scale unlike alkalinity. You can have an acidic solution with a high alkalinity.

Thank you do I guess therefore look another water or boil with gypsum for 30 to reduce the carbonate for a n9n black beer. Rough measure but helps. Pretty standard technique for mid Essex waters

Justin Dean said:

Thank you for the advice so for Lidl Clarity Springs bicarboinate is 135 mg per litre therefor divide by 1.22 is 110.65, what does that mean, good or Is that the key figure to use in the calculator then adjust to suit the beer you are making? i thought ph reflected acidity and alkalinity and you want ph of about 6.5 mostly. Lidl clarity springs is ph 7.8 at source but according to my aquarium test strips it is 7 in the bottle, which is close enough.....

Click to expand...

Alkalinity (as CaCO3) and bicarbonate (as HCO3-) have little to nothing to do with water pH. For example, my well water measures 436 mg/L as to alkalinity and 532 mg/L as to bicarbonate, but its pH is 7.2. Very close to neutral.

Justin Dean said:

Thank you do I guess therefore look another water or boil with gypsum for 30 to reduce the carbonate for a n9n black beer. Rough measure but helps. Pretty standard technique for mid Essex waters

Click to expand...

It depends on what you want to brew. You can increase calcium by adding gypsum or calcium chloride and you can reduce alkalinity by acidifying with CRS or lactic acid (much easier and quicker than boiling). Have a look at the OP which tells you how to tailor the water profile to the style of beer you want.

My Anglian water report from 2018 which is the most recent version available says


Hardness: Very Hard
Total hardness as Calcium 168.5mg/l
Total hardness as Calcium carbonate: 421.25 mg/l

Alkalinity (As Calcium Carbonate: 336 mg/l (I did Siefert KH/Alk test on the water from my filter tap and I reckon it is about 281 from a test today)


Calcium: 124 mg/l
Chloride: 96.6 mg/l
Chlorine (free): .46 mg/l
Chlorine (total): 0.55 mg/l
Fluoride: 0.841 mg/l
Iron: <7 μg/l
Magnesium: 26,8 mg/l
Nitrate: <3.763 mg/l
Nitrite: <0.009 mg/l
Potassium: 9.96 mg/l
Sodium: 61.7 mg/l
Sulphate: 73.4 mg/l


My data form above says Alkalinity (As Calcium Carbonate) is 281 mg/l, "For a pale beer <20ppm"? i.e. would I be aiming to reduce alkalinity by 261 or so to hit 20ppm for a pale beer? . ?
So if I'm using 27L of water for a batch (Grainfather 11l for the mash and 16l sparge kettle). The scale your guidance allows for an adjustment of 200, I need to adjust by 261 to get 20ppm. Extrapolating the scale up then you say 1.367 ml per l to adjust down to 20 ppm where I am


my gut feel is this is a most unlikely adjustment for the guidance above, so it is matter of using bottled water instead otherwise I'd be looking to add:


half a Camden tablet
15.04ml for the mash of CRS (1.367 times 11) reduction of 260 ppm. For the sparge 21.88ml of CRS (1.367 times 16) IS THIS REASONABLE?


My water report states 124 mg/L Calcium so that should be ok as it's higher than the 100ppm suggested, or I could be aiming nearer 150ppm for the hoppy beers I like, I could ass maybe 3g of gypsum in all split between the 11 and 16 litres in the mash and the spurge, but it is close enough?


If you can confirm my thoughts above? That would help me to conclude my thoughts on this please. I do find this rather confusing but this is where I am at the moment

Question - if I remove 220 ppm alkalinity with CRS (mix of hydrochloric and sulphuric acid ) how much do chloride and sulphate go up ?

If I calculated it correctly, a reduction of 220 ppm alkalinity in 27 liters of water via the use of CRS/AMS should add ~73 ppm of chloride and ~100 ppm of sulfate to your water (give or take a few ppm).

Many thanks, Argentum............

Any ideas on my post above?

Justin Dean said:

Any ideas on my post above?

Click to expand...

Have you tried plugging your numbers into the calculator? https://www.thehomebrewforum.co.uk/pages/water-calculator/

I am also anglian water see my post up a bit....

The calculators is confusing but will try again. And thx Bob. Where are you mate? Anywhere near Braintree?

Bob is Northamptonshire - meet you in London ?

I rarely go into London mate. Did that for years.