Determining sulphate content

[MillmoorRon]

Is there a home test kit that can determine reasonably accurate sulphate levels?

[Dave S]

Is there a home test kit that can determine reasonably accurate sulphate levels?

You'd be better getting a proper analysis done on your tap water. If you PM Wallybrew he'll do a comprehensive analysis for you at a very reasonable price.

[MillmoorRon]

Given the large range of values and sudden swings of my water supply, I would have to get the mysterious PM Wallybrew to test my water every time I wanted to do a brew, which I suspect would be very expensive. Also, I would have to hope that there were no changes whilst the sample was away for testing!

It would be useful to be able to do a test myself on the day of brewing.

[Aleman]

The simple answer is no there isn't.

Now for the slightly more complicated answer.

Get hold of a Salifert Total Alkalinity test kit, a Salifert Calcium Test kit and an el cheapo TDS meter from china.

Using your test kits, and the TDS meter, measure your water content. Note the results and send a sample to Neil (Phoenix Analytical - Wallybrew). Compare with what you get back.

Brew a few more times measuring Alkalinity, Calcium and TDS. Make an educated guess as to the other ions as a ratio based on your curren measurements compared to Neils.

When you get a massive high or low value for alkalinity / Calcium / TDS send another sample to Neil for analysis.

My water swings a lot but I can reasonably predict what my ion content is based on an alkalinity and TDS reading from the max and minimum values that I have from Neil.

Yeah it's never going to be perfect, but unless you have an all singing all dancing water testing machine, like the one I've been asked to test by a homebrew retailer then you can only make a guess, and an educated guess is better than a finger in the air guess

[MillmoorRon]

How would I interpret a TDS reading?

A quick search brought this up:

Total dissolved solids (TDS) comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and some small amounts of organic matter that are dissolved in water.

If the other constituents listed above were known, could I estimate sulphate levels from the TDS value? (disregarding the 'small amounts of inorganic matter')

I'll do a bit more research into TDS at the weekend.

[f00b4r]

Unless you have an all singing all dancing water testing machine, like the one I've been asked to test by a homebrew retailer then you can only make a guess, and an educated guess is better than a finger in the air guess

Now that is a tease but interesting someone is trying to fill that gap in the market!
I guess accuracy and price pont will determine its usefulness for most people.

[Dave S]

How would I interpret a TDS reading?

A quick search brought this up:

Total dissolved solids (TDS) comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and some small amounts of organic matter that are dissolved in water.

If the other constituents listed above were known, could I estimate sulphate levels from the TDS value? (disregarding the 'small amounts of inorganic matter')

I'll do a bit more research into TDS at the weekend.

Measure the TDS value of the sample you send to Neil and record it. Once you have an analysis from Neil you can compare subsequent values that you get with that. Then if your alkalinity and Calcium levels also compare with Neil's, you can reasonably assume that your overall profile hasn't altered.

BTW, it's the small amount of organic matter that can be disregarded.

[MillmoorRon]

BTW, it's the small amount of organic matter that can be disregarded

Sorry, typo!

From what I've read TDS is basically the sum of all the other bits mentioned above, plus some other less significant ones.

So should I be able to get a reasonable estimate of sulphate levels from the TDS after testing using my Salifert kits for the other wide-ranging constituents?

Found this whilst surfing: http://www.lovibondwater.com/product/af ... t-kit.aspx

Seems to be about £40 but does 100 tests. Anybody used one of these?

[Dave S]

BTW, it's the small amount of organic matter that can be disregarded

Sorry, typo!

From what I've read TDS is basically the sum of all the other bits mentioned above, plus some other less significant ones.

So should I be able to get a reasonable estimate of sulphate levels from the TDS after testing using my Salifert kits for the other wide-ranging constituents?

Found this whilst surfing: http://www.lovibondwater.com/product/af ... t-kit.aspx

Seems to be about £40 but does 100 tests. Anybody used one of these?

I wouldn't go to the expense. As Aleman has said, if you've got Alkalinity, (Salifert), Calcium, (Salifert) and TDS and these figures compare with your results from Neil, then you can be reasonably assured that the rest will also compare with Neil's analysis.

Also, the ad for that kit says in one part that it measures 40 - 4000 mg/L of sulphate and in another, 40 - 200. I'm guessing the latter is more likely, but even that can be outside the range of some domestic waters. Mind you, if you had 4000 mg/L you'd be drinking it with a spoon.

[Eric]

A TDS meter will come calibrated as if all the dissolved solids are one material, usually common salt. Tap water will have only a proportion of sodium chloride so any reading can be misleading.
I have two TDS meters, both of which were found to be adjustable. One was recalibrated in a sample of the water sent to WallyBrew for analysis to his findings and is used extensively to good effect.
The cost of the meter plus testing is trivial in comparison to its power and time saving on brewdays.