Gypsum

[McMullan]

How accurate are these Salifert kits? They seem quite cheap. I'm guessing some basic titration of some kind. Do you need to measure precise volumes?

 

[TartanSpecial]

Especially if we are basing it on 2014 average data, and on a water calculator that differs from other water calculators etc?

These values are based on testing the water we are currently getting through the tap with the test kit. Murphy's recommendation, the old calculator and the graham wheeler one all come up with similar results as regard translating the alkalinity result to CRS treatment.

 

[TartanSpecial]

How accurate are these Salifert kits? They seem quite cheap. I'm guessing some basic titration of some kind. Do you need to measure precise volumes?

They claim to be accurate to the equivalent of 5 ppm alkalinity (as Ca CO3) as long as you get the end point of the titration correct.Volumes of the test sample are using a 5ml syringe, and the reagent is dropped into the water /indicator dye mix from a long 1ml syringe with an ultra fine tip.

 

[ManseMasher]

Top notch service? 2014 results? Give over! :)

I think you'll find most water suppliers latest test results will be 2014 - Sussex was last time I checked. They publish the results annually, but test a lot more frequently. And I was commenting on the customer service, not the testing regime.....

 

[clibit]

Yeah ok,I'm all for reducing carbonates if your water is hard. And adding calcium where appropriate. They seem to be the key water issues.

 

[peebee]

Gawd this whole water treatment is so confusing ...

You might have read me whinging about this in another post today.

They seem to enjoy measuring things "as if" it has so much (in this case chalk) in the water. Not that there is that much (chalk) in the water. And just in case that isn't confusing they use the same measure ("as if" there is this much chalk...) to measure something else! "Hardness" and "alkalinity" being a very good example; both may be declared "as mg/L of CaCO3" but have differing values. That's because they are measuring both "as if" its chalk (CaCO3) doing it, not telling you how much chalk there is doing it!

Confused before you read this? Be careful, you might be suicidal now!

And I'm not even sure I've got it right!

 

[peebee]

And those Salifert kits...

Well they certainly helped me get my head around all this.

But I live in a "soft" water area. I set everything up and... the colour changed with two minuscule drops. Wasn't expecting that! So had to do it again a little bit more carefully!

 

[McMullan]

They claim to be accurate to the equivalent of 5 ppm alkalinity (as Ca CO3) as long as you get the end point of the titration correct.Volumes of the test sample are using a 5ml syringe, and the reagent is dropped into the water /indicator dye mix from a long 1ml syringe with an ultra fine tip.

Have you tried repeating measurements on the same sample to check how consistent the results are? Sounds like a small volume (uL) pipette would be very useful.

 

[MyQul]

You might have read me whinging about this in another post today.

They seem to enjoy measuring things "as if" it has so much (in this case chalk) in the water. Not that there is that much (chalk) in the water. And just in case that isn't confusing they use the same measure ("as if" there is this much chalk...) to measure something else! "Hardness" and "alkalinity" being a very good example; both may be declared "as mg/L of CaCO3" but have differing values. That's because they are measuring both "as if" its chalk (CaCO3) doing it, not telling you how much chalk there is doing it!

Confused before you read this? Be careful, you might be suicidal now!

And I'm not even sure I've got it right!

I think you've used up your whinginh quota for the day :lol:

I'm confused before and after reading it :lol:

 

[TartanSpecial]

I did a couple of tests a few days apart. First one came out at 275ppm as CaCo3 and the second one , where I was being ultra careful to get the endpoint right and not over-run came out at 268ppm.... so not too bad. Next time I brew I might do 2 tests on the same water. Yeah...their syringe method is pretty basic....in a proper lab you'd use a more dilute solution of reagent so could judge the end point more accurately...but its not bad for a £5 test kit.

 

[peebee]

Have you tried repeating measurements on the same sample to check how consistent the results are? Sounds like a small volume (uL) pipette would be very useful.

I'll barge in and answer this. The syringe (1ml) is more than adequate. It's the reagent that dictates how accurate it is.

(Ha, didn't barge in quick enough!)

 

[McMullan]

I did a couple of tests a few days apart. First one came out at 275ppm as CaCo3 and the second one , where I was being ultra careful to get the endpoint right and not over-run came out at 268ppm.... so not too bad. Next time I brew I might do 2 tests on the same water. Yeah...their syringe method is pretty basic....in a proper lab you'd use a more dilute solution of reagent so could judge the end point more accurately...but its not bad for a �£5 test kit.

That sounds consistent enough. Is the procedure straight forward and quick?

 

[McMullan]

I'll barge in and answer this. The syringe (1ml) is more than adequate. It's the reagent that dictates how accurate it is.

(Ha, didn't barge in quick enough!)

The volume of the reagent added?

 

[MyQul]

That sounds consistent enough. Is the procedure straight forward and quick?

Yes. If I can do it you certainly will be able to. Takes about 5 or 10 mins.

If you've got hard water though the first time you'll get a bit exasperated as you put the one liquid into the ther drop by drop, until the reagent turns pink. If you have hard water you'll need a hell of a lot of drops. But subsequent times you know approx where the reagent will change colour so you can push the plunger down to near where it was the last time and only then have to add the liquid drop by drop

 

[BeerCat]

Yes Belfast here, I'm unsure of my water profile although I do know it's pretty clean at around 8-10ppm total dissolved solids (TDS). We don't suffer from limescale although that could be due to a low TDS.

Recipe (to be adjusted for a 21L brew as I'm metric)

5lb Pale Malt, (I'll use Irish Stout Malt)
2lb Flaked Barley
1lb Black Barley
2.25oz EKG (probably use whatever I have in the fridge and adjust)
Irish Moss
Gypsum
5 gallon water (it recommends Dublin water profile as it's a Guinness clone)
Wyeast Labs #1084

Wow, that's really low. The same as my re mineralising RO system. My tap water is about 250.

 

[McMullan]

Yes. If I can do it you certainly will be able to. Takes about 5 or 10 mins.

If you've got hard water though the first time you'll get a bit exasperated as you put the one liquid into the ther drop by drop, until the reagent turns pink. If you have hard water you'll need a hell of a lot of drops. But subsequent times you know approx where the reagent will change colour so you can push the plunger down to near where it was the last time and only then have to add the liquid drop by drop

I think I'm getting the idea :thumb: The colour change (volume added) is then related to a chart of some kind? I tried their website for info, but it's all 'under construction'. Sounds good for monitoring certain aspects of water over time. I might have to get one or two of these kits. A lot cheaper than a one-off pro analysis.

 

[MyQul]

QUOTE=McMullan;539493]I think I'm getting the idea :thumb: The colour change (volume added) is then related to a chart of some kind? I tried their website for info, but it's all 'under construction'. Sounds good for monitoring certain aspects of water over time. I might have to get one or two of these kits. A lot cheaper than a one-off pro analysis.[/QUOTE]

Heres' a full (pictorial) explanation on jims

http://www.jimsbeerkit.co.uk/water_salifert.htm

 

[peebee]

The volume of the reagent added?

That's it. The "resolution" is documented as "0.3dKH". If such a step needs more than 0.01ml of reagent from the syringe (the graduations on the syringe) there is no point delivering less than 0.01ml.

 

[clibit]

A video showing an alkalinity test...

https://youtu.be/qZ91rcecShM

 

[TartanSpecial]

and the kit does 100-200 tests depending on how hard your water is...hard water uses more reagent before the indicator dye colour changes. So ultra cheap per test.