RO Water Sample Testing

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

thegrantickle

Regular.
Joined
Nov 2, 2020
Messages
299
Reaction score
149
Hi All,

I have an RO system, and I love it! Adjusting water chemistry has given me so much more control over my beers! I use Bru'n'Water for my water chemistry, and I'm currently using the RO profile in there set to 100% dillution. However, I am really interested in finding out what the mineral make-up of my RO water actually is!

TL;DR: Can anyone recommend a UK based water testing lab who can test a sample for mineral content, alkalinity and pH, inexpensively?

Ta
 
Hi All,

I have an RO system, and I love it! Adjusting water chemistry has given me so much more control over my beers! I use Bru'n'Water for my water chemistry, and I'm currently using the RO profile in there set to 100% dillution. However, I am really interested in finding out what the mineral make-up of my RO water actually is!

TL;DR: Can anyone recommend a UK based water testing lab who can test a sample for mineral content, alkalinity and pH, inexpensively?

Ta
If your filter is good it should be virtually zero across the board. Have you tried a TDS meter to see how effective it is? 🍺
 
Same here. My RO gets it down to about 5. I can deal with 5 and not have to know!
Aye i agree it's probably irrelevant at that level. The accuracy of my 0.01g scales is going to have more effect that the odd stray ion here or there. I just HATE looking at water calcs and seeing the numbers that it estimates for RO water and having no clue if they are right or not haha
 
I was advised by several here that using 100% RO is a bit over the top, and may mean that you’re taking minerals out only to add them back in again - and also inadvertently removing trace elements that are good for yeast health (eg Zinc).
Personally unless I’m doing a Pilsner or similar I use 50% dilution to get the calcium down a bit and that gives me a great starting point to create pretty much any profile - and my water is hard as nails :-)
 
Aye i agree it's probably irrelevant at that level. The accuracy of my 0.01g scales is going to have more effect that the odd stray ion here or there. I just HATE looking at water calcs and seeing the numbers that it estimates for RO water and having no clue if they are right or not haha

I understand, I have loads of little things that get to me if it’s an unknown or not quite right. If it irks you and you need to know then it’s probably worth getting it tested.

I had my tap water tested by Murphy and sons. I suppose you can do the same with RO?

The problem is that as the filter gets older it gets less efficient and the numbers would change anyway.
 
I understand, I have loads of little things that get to me if it’s an unknown or not quite right. If it irks you and you need to know then it’s probably worth getting it tested.

I had my tap water tested by Murphy and sons. I suppose you can do the same with RO?

The problem is that as the filter gets older it gets less efficient and the numbers would change anyway.
This is true, im gonna replace the filters every 6 months or so cause they're not that expensive. Murphy and Sons - I shall look into that! Cheers bud. How much did it cost you?
 
This is true, im gonna replace the filters every 6 months or so cause they're not that expensive. Murphy and Sons - I shall look into that! Cheers bud. How much did it cost you?

Thinking about it, it’s probably time I change my filters too.

I think it was around £25 or so. There may be some cheaper ones but couldn’t find any at the time.
 
Hi All,

I have an RO system, and I love it! Adjusting water chemistry has given me so much more control over my beers! I use Bru'n'Water for my water chemistry, and I'm currently using the RO profile in there set to 100% dillution. However, I am really interested in finding out what the mineral make-up of my RO water actually is!

TL;DR: Can anyone recommend a UK based water testing lab who can test a sample for mineral content, alkalinity and pH, inexpensively?

Ta

Try this chap, here is my RO.

 
If you’re using the four stage RO machine from Vyair (I know many do) then you should have nothing in the water momentarily, not even ions because the de-ionisation crystals will have removed those. My TDS reading is zero and Vyair recommend replacing the de-ionisation crystals when the TDS reads 1! You can see when they need changing because they turn from green/black to orange. The pH will be 7.00 but not for long…

Pure water very quickly absorbs CO2 from the air which turns it acidic and my pH is often between 5.5 and 6.5 when I start my brewday. This has no impact whatever on your mash pH however because the water has no buffering potential - by that I mean the slightest alkaline addition will neutralise the acidity. In addition, the CO2 escapes back into the air as the water is heated. Bottom line - treat it as pH 7 even if your pH meter says it’s lower.
 
If you’re using the four stage RO machine from Vyair (I know many do) then you should have nothing in the water momentarily, not even ions because the de-ionisation crystals will have removed those. My TDS reading is zero and Vyair recommend replacing the de-ionisation crystals when the TDS reads 1! You can see when they need changing because they turn from green/black to orange. The pH will be 7.00 but not for long…

Pure water very quickly absorbs CO2 from the air which turns it acidic and my pH is often between 5.5 and 6.5 when I start my brewday. This has no impact whatever on your mash pH however because the water has no buffering potential - by that I mean the slightest alkaline addition will neutralise the acidity. In addition, the CO2 escapes back into the air as the water is heated. Bottom line - treat it as pH 7 even if your pH meter says it’s lower.
That's some good advice - thank you. It's indeed the Vyair 4 stage, which I've found superb to be honest. It's been giving me 2 TDS since the day I got it, about 3 months ago, so I guess that's as good as its gonna get. I never really thought about absorption and dissolution of CO2, but of course that makes perfect sense!
 
That's some good advice - thank you. It's indeed the Vyair 4 stage, which I've found superb to be honest. It's been giving me 2 TDS since the day I got it, about 3 months ago, so I guess that's as good as its gonna get. I never really thought about absorption and dissolution of CO2, but of course that makes perfect sense!
That’s interesting. Assuming everything is working correctly including your TDS meter you are still managing to get a little something in your otherwise purified water. It might be worth running off a little RO water (just enough to test with your TDS meter) but with your water pressure set lower. It *may* be possible that at full pressure you’re managing to push the odd molecule of something other than water through the membrane?
 
That’s interesting. Assuming everything is working correctly including your TDS meter you are still managing to get a little something in your otherwise purified water. It might be worth running off a little RO water (just enough to test with your TDS meter) but with your water pressure set lower. It *may* be possible that at full pressure you’re managing to push the odd molecule of something other than water through the membrane?
Could be the TDS to be fair (it's an amazon jobby). Water pressure isn't *that* high as is, and I don't think I have any way of turning it down.
 
Hi All How often are we changing our colour change resin ?
I only seem to get about 150 L of RO before I need to change it
I still haven't changed mine yet, have probably had about 1000L easy from it and it's still got no sign of changing colour. Suppose it depends on what the source water is like?
 
Back
Top