Pond water test kit

[Lugsy]

Hi all

I'm just about to start playing around with water testing/treating and before I go out and buy a Salifert test kit for alkalinity I was wondering if I can use a pond test kit I already own. It's an NT Labs Pondlab multi-test kit that measures alkalinity (KH) and general hardness (GH) among other things.

The KH test involves adding a reagent to a 5ml sample of water one drop at a time until the mixture turns from blue to yellow. When I test my tap water it takes seven drops of the reagent to turn the mixture yellow which apparently corresponds to an alkalinity of 125 ppm of CaCO3.

The GH test involves adding 5 drops of reagent "A" to 5ml of water and then adding reagent "B" one drop at a time until the colour changes from purple to blue. This takes 12 drops with my sample of water which, confusingly, apparently corresponds to 216 ppm of CaCO3.

A couple of questions then. Firstly, am I meant to be measuring alkalinity (KH) or general hardness (GH) for treating my brewing liquor? Secondly, what does the ppm measurement correspond to in terms of mg/l or is it just the same number? Thirdly, given that the two results differ wildly should I just stop being such a skinflint and go out and spend a few quid on a Salifert kit?

By the way, I've looked at a water report for my area which gives a measurement of between 70 and 119 mg/l of calcium and a general hardness of between 81 and 134 mg/l of calcium. Having said that, the report is from 2009 so might not be too reliable!

Cheers!

[testtube]

Maybe I'm wrong but I don't see why you need to do that. I read my water report, adjust with gypsum, calcium chloride etc. to what beer I'm making and check my mash PH which is always ok.

[Lugsy]

I was under the impression that your water composition changes significantly from one day to the next. If not then I'll happily go with the two year old water report and adjust accordingly rather than mess around with testing it myself!

[testtube]

Errrrr get an up to date report! United Utilities update them on their website all the time, everyday I think!

[testtube]

Just to add, there are fairly large tolerance's with water treatment. If you just take the average it will be fine.

[Kev888]

My lot only give annual reports and they're only averages at that - sadly in my case the averages are not safe to use as they belie the 'extremely' wide range that can occur. Generally my tap water tends to be fairly stable but from time to time it can change very radically (presumably if they start drawing water from a different source). I guess if your company update every day (thats really impressive!!) and you fill the HLT 24hrs before any report then maybe its not such an issue.

I'm not sure about the pond test kit, but its definately total alkalinity rather than hardness that you want to measure. This post will tell you lots, and the brewniversity here has a water testing/treatment how-to which includes a useful guide on the the salifert stuff

Cheers
kev

[testtube]

They test by law, some things every 2 hour's and the result's are public, so if you can't get a report there is something wrong. Only trying to help here, I don't understand why people use campden tablet's, my water contain's hardly any chlorine, and whatever is there is gone when I've heated the water above 60'C! People mistake the smell of their water having chlorine when they are smelling flouride! Please take note of the tolerance's involved including those of your test kits! And most of all the flavour of your beer......

[jmc]

They test by law, some things every 2 hour's and the result's are public, so if you can't get a report there is something wrong. Only trying to help here, I don't understand why people use campden tablet's, my water contain's hardly any chlorine, and whatever is there is gone when I've heated the water above 60'C! People mistake the smell of their water having chlorine when they are smelling flouride! Please take note of the tolerance's involved including those of your test kits! And most of all the flavour of your beer......

Hi

The main reason I use campden tablets is because my supply has chloramines in it.

Unfortunately they don't boil off so 1 campden tablet per 50L of water sorts the problem.

Its simple & it works so why not use it?

BTW: My local company (in Bedfordshire) produce water reports every 6 months or so.

ATB
John

[Kev888]

Yeah, +1. Also I seem fairly insensitive to the taste of chlorine/chloromines so I like to be sure friends etc aren't tasting things i'm not able to quality control by taste alone.

Testtube, I wasn't disagreeing as such - really just mentioning that your water company seems unusually progressive; i wish mine was!

My lot don't seem to extend themselves much beyond the legal requirements (or don't report it if they do), and I believe what they are actually required to test regularly is very limited indeed (mostly to things which are perceived to affect health) and even there there's no requirement for them to publish as often as they test. The annual report I get says how many samples the averages were derived from and sometimes its pitiful for things useful to the brewer, not even every two months in some cases let alone hours. And they don't even bother to include total alkalinity (not to mention a number of other useful things) as its 'not a required control' measure - though I'm sure one could ask for them if they measure it, I feel its more reliable to go with a test kit (of reasonable if not great accuracy) over an average based on very few samples annually.

There was a period one summer during which whenever I filled the bath I got an overwhelming chlorine-ish stink from it, and the water seemed very artificially blue too; It could have been flouride or something for all I know and thankfully I wasn't brewing from it before I realised as i'm not sure what i could have done about it, but it illustrated to me very vividly how things can suddenly vary - there's no way my companies' annual reports are up to that type of thing.

Cheers
kev

[Aleman]

I too get my water from United utilities and Sorry but Test Tube you are wrong . . . many of the things that we need to 'know' in brewing are only measured once or twice a year (the report gives a Min/Max/Average and No Of Readings) which quite frankly makes it more or less useless for the two most important brewing factors (alkalinity KH, and Calcium). For years my alkalinity level has been stable at 20-24mg/l . . . but last year it suddenly rose to 134mg/l, and has been fluctuating between 30 and 70mg/l over the last 9 months. . . . Unless I adjusted my liquor treatment to take this into account the effect it would have on my beers would be dramatic.

To the OP - The reason the Salifert Total Alkalinity test kit has been recommended so much, is that it is much more consistent than a lot of the other test kits, and the results agree closely with other, laboratory, analytical methods

[testtube]

No, sorry... they check every 2 weeks on mine, at least. When it went up they might have got some water from somewhere else as they were running short, they do that with ours, pump it in from the lakes. Maybe they would send you a report? Something fishy here! Feel sorry for you fella's if it's like that.

I treat my water.. For a particular beer the range for say calcium is 100ppm, I'm also lucky to have soft water, so taking the average and treating correctly I know I'm within a given range. But if I made a dark beer and adjust my water just on alkalinity and calcium, I would be doing more harm than good. I think I'll get one of these kit's to check. I hope you see where I'm coming from as I do see people making a arse of it.

[Aleman]

No, sorry... they check every 2 weeks on mine, at least. When it went up they might have got some water from somewhere else as they were running short, they do that with ours, pump it in from the lakes. Maybe they would send you a report? Something fishy here! Feel sorry for you fella's if it's like that.

This is a portion of the current report from united utilities for all bar one of the important brewing parameters for my water zone

The report details drinking water quality for the last 12 months. The information is updated weekly.

It does appear that they are taking more samples than they used to, but still not frequently enough, and most importantly they don't tell when the last reading was taken and what it was . . . and what it was on the day I drew the liquor to brew with. . . . . Could I accept the 'average' value . . . possibly, but not for alkalinity, which is why people need to measure it before brewing.

Code: Select all

Parameter	                 Min    Average    Max  Units     Regulatory Standard	Number of samples	% failed
Calcium                     16.4     33.7     54.7  mg Ca/l                                41            0
Chloride                     4.51     9.1     21.1  mg Cl/l           250                  75            0
Magnesium                    2.8      7.33    12.3  mg Mg/l                                41            0
Sodium                      10.2     19.1     28.1  mg Na/l           200                  41            0
Sulphate                     7.09    39.5    121    mg SO4/l          250                  70            0
Residual chlorine - Total    0.08     0.49     1.05  mg/l                                 115            0
Residual chlorine - Free     0.04     0.43     0.81  mg/l                                 115            0

[Lugsy]

Err, sorry fellas, I didn't mean to start a fight!

I've done a bit of research and it looks like ppm and mg/l are interchangeable when you're talking about aqueous solutions so I'll have a go at treating with AMS according to my test kit's result for KH. I know my water's pretty hard looking at the inside of my kettle and from the water report so I'm happy to go with the KH measurement I get.

I'm doing a TTL recipe at the weekend so I'll try to adjust down to the required 30mg/l of CaCO3 from my measurement of 125mg/l. I figure that if my alkalinity is higher than that then at least I'll be adjusting part of the way in the right direction and under-doing it rather than turning my liquor into something that'll eat it's way through the pan

Please correct me if I'm wrong!

[Eric]

I use an alternative kit too. I don't know how accurate either it or the Salifert is but I would hope the indicator would be near enough correct in both. This being so, it would be possible to determine the neutral point and if not, the kit is not simply inaccurate, it would be in practical terms, useless.
If we were to assume your kit is accurate to within plus or minus 50% (I would expect much better than this) then your kH measurement of 125 would mean you had between 62 and 187 mg/L CaCO3. If you were carry out treatment and test again to get a reading of 30, the final alkalinity would be between 15 and 45 mg/L CaCO3, whichever way you look at it, an improvement.
Good luck.

[testtube]

Yeah ppm and mg/l are the same. Your sparge liquor wants to be low like 30 (Think I'd have to check).. The rest depends what your brewing really.. 125 will be ok for toasted malt beer.. Assuming CaCo3. Would be a good idea to check your mash pH..Think aleman is going to split a brain cell again!