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Cambridge tap water ICP-MS results

Joined
31 Aug 2020
Messages
76
Location
Cambridge
Hello, I have recently received results for mass-spectography analysis of the Cambridge city tap water which includes some interesting meausures that are not usually listed in the official water company reports.
ElementDimTap waterTap water tank (EI)50/50 RO/Tap tank (EI)50/50 Tank after 3x 50% changes
Liug/l
7,9​
8​
4,5​
4,1​
Beug/l
< 0,03​
< 0,03​
32​
< 0,03​
Bug/l
25​
120​
60​
47​
Namg/l
11​
19​
9,9​
8,1​
Mgmg/l
4,2​
10​
11​
7,7​
Alug/l
< 0,25​
< 0,25​
< 0,25​
< 0,25​
Siug/l
-​
-​
-​
-​
Pug/l
740​
1160​
1240​
340​
Smg/l
-​
-​
-​
-​
Clmg/l
24​
30​
14​
15​
Kmg/l
2,1​
27​
43​
12​
Camg/l
110​
110​
52​
52​
Tiug/l
0,17​
0,4​
0,53​
0,2​
Vug/l
0,089​
0,25​
0,048​
0,059​
Crug/l
0,25​
0,7​
0,17​
0,096​
Mnug/l
0,04​
< 0,0125​
0,13​
0,024​
Feug/l
180​
340​
250​
110​
Coug/l
0,16​
0,82​
0,57​
0,21​
Niug/l
3​
4​
5,1​
1,8​
Cuug/l
21​
14​
16​
11​
Znug/l
3,2​
45​
93​
41​
Gaug/l
0,0064​
13​
11​
0,0049​
Geug/l
0,08​
0,2​
0,18​
61​
Asug/l
0,22​
0,72​
0,26​
0,12​
Seug/l
0,63​
0,42​
< 0,2​
< 0,2​
Brug/l
-​
-​
-​
-​
Rbug/l
1,6​
11​
13​
4,7​
Srug/l
430​
450​
180​
190​
Zrug/l
< 0,05​
0,12​
< 0,05​
< 0,05​
Nbug/l
0,0085​
25​
11​
0,0048​
Moug/l
0,35​
1,2​
5,4​
2,9​
Agug/l
0,047​
0,14​
0,064​
0,0077​
Cdug/l
0,003​
0,0043​
0,0065​
0,0032​
Snug/l
< 0,003​
0,15​
0,097​
0,012​
Sbug/l
0,066​
0,11​
0,12​
0,065​
Teug/l
0,0094​
0,016​
0,02​
0,011​
Iug/l
2,5​
0,32​
0,3​
0,83​
Csug/l
0,011​
0,037​
0,038​
0,013​
Baug/l
61​
50​
12​
14​
Laug/l
< 0,0005​
< 0,0005​
0,0014​
< 0,0005​
Ceug/l
< 0,0005​
0,0014​
0,019​
< 0,0005​
Prug/l
< 0,0005​
0,0034​
0,0079​
< 0,0005​
Ndug/l
< 0,0025​
< 0,0025​
0,0059​
< 0,0025​
Smug/l
0,00085​
0,0069​
0,011​
0,0023​
Euug/l
0,0071​
0,0079​
0,0039​
3​
Gdug/l
< 0,0005​
0,0057​
0,0083​
0,0015​
Dyug/l
< 0,0005​
0,0075​
0,011​
0,0014​
Houg/l
< 0,0005​
0,0011​
0,0019​
< 0,0005​
Erug/l
< 0,0005​
< 0,0005​
0,0035​
< 0,0005​
Tmug/l
< 0,0005​
< 0,0005​
0,0009​
< 0,0005​
Ybug/l
< 0,0005​
0,0068​
0,013​
0,0031​
Hfug/l
0.095​
0,19​
0,11​
0,06​
Taug/l
0,0028​
0,0046​
0,0029​
< 0,0025​
Wug/l
< 0,0025​
0,0068​
0,011​
0,0062​
Hgug/l
< 0,025​
< 0,025​
< 0,025​
< 0,025​
Tlug/l
0,01​
0,0094​
0,0097​
0,0059​
Pbug/l
0,094​
< 0,025​
< 0,025​
< 0,025​
Thug/l
0,017​
0,067​
0,029​
0,0095​
Uug/l
0,42​
0,013​
0,03​
0.033​

Interesting thing is the amount of Manganese: it clearly looks like a limiting factor for plants as it disappears quickly in the tanks despite of EI dosing. Zn and B seems to be accumulating slightly on the contrary. I'm also quite surprised to see that much Iron in the tap water, but MS catches also colloid Iron (e.g. from the tubes) that is not really solluble. Same is valid for Phosphorus: ICP-MS can even find organic Phosphorus in algae cells. They were not able to find quantities of Br, Si and S because of the technical issue. That analysis was done using Bruker Aurora M90 ICP-MS analyser.

So our tap water is very poor in Magnesium (so I add it for all tanks), Potassium and Sodium. Manganese is definitely something I need to think about when mixing micro...
 
So our tap water is very poor in Magnesium (so I add it for all tanks),
I think @dw1305 has a map in here showing the geology in the UK. There aren't many places where Mg is coming out the tap. It has only started coming out of my tap lately according to the latest water report since they started blending the local reservoir water with an underground aquifer.
 
I have recently received results for mass-spectography analysis of the Cambridge city tap water
Impressive.
Interesting thing is the amount of Manganese:
Yes it does seem to be getting 'moped' up quickly by the plants with a weekly EI dose being about 0.1ppm Mn when using APFUK trace
I'm also quite surprised to see that much Iron in the tap water

similar levels here in Yorkshire, however we do get a big 'swing' over the seasons

So our tap water is very poor in Magnesium

about 5ppm Mg is about normal for most of UK.

I expected to see more K as well, water company's rarely report on K as there is no legal limit.
Manganese is definitely something I need to think about when mixing micro...

Based on your report I would have to agree.

Can we send you some water samples for analysis :angelic::lol:
 
think @dw1305 has a map in here showing the geology in the UK. There aren't many places where Mg is coming out the tap.
Yes, I have read that. I wanted mostly to check potassium levels in tanks and in the tap as potassium test kits are rubbish (e.g. EL test kit has shown 20ppm K in RO water with TDS=2). But checking other elements were very useful and Mn/Fe results were even quite surprising to me.
Yes it does seem to be getting 'moped' up quickly by the plants with a weekly EI dose being about 0.1ppm Mn when using APFUK trace
I've been adding 0.1ppm Fe daily tap water tank using APFUK mix. In 50/50 tank that micro dosing had caused heavy melting issues, so I had to dose it at 0.05ppm Fe level adding additional Fe from Seachem Iron. For now, I mix APFUK (0.05) with Chempack Iron (2% Fe, 3% Mn, 6% Mg) at 0.05ppm and add some more Fe Gluconate from Seachem Iron. And it seems to be good for L. Aromatica and does not cause melting. From ICP results, I suppose that the culprit of melting was Boron.

As you see, Boron level is around 0.12ppm in the tap water tank. But that tank is malawi cichlid tank planted with very hardy plants (tonns of Vallisneria, Echinodorus, Cryptocorine etc), so that dosing has not caused any issues. Suprisingly tap water cichlid tank has almost no algae, even on glass, whilst 50/50 RO tank has constant issues with staghorn...
Can we send you some water samples for analysis
I have done that by sending water samples to Moscow :) The cost of each analysis was around 10£ and mail costs are around 3-4£ (for any number of samples). If that looks reasonable please PM me, so I can act as a water proxy ;) They do both fresh and seawater analysis (promising Br, S and Si being fixed 'soon').
 
And, erm, for some elements I've lost 0,0 in when copying table, e.g. Be or Ga - so when results in tap are like 0,013 and in aquarium like 13 means that 0,0 was missed out...
 
I'm also quite surprised to see that much Iron in the tap water...
Hi @Vsevolod Stakhov

I'm going to take a thorough look through these figures later. But, the iron figure is very much in line with my water company's 2019 report. To be specific:

Min : 3.00 micrograms/l
Mean: 21.98 micrograms/l
Max: 217.30 micrograms/l

The PCV* for iron is 200 micrograms/l.

*PCV = Prescribed Concentration or Value

JPC
 
I have done that by sending water samples to Moscow :) The cost of each analysis was around 10£ and mail costs are around 3-4£ (for any number of samples). If that looks reasonable please PM me, so I can act as a water proxy ;) They do both fresh and seawater analysis (promising Br, S and Si being fixed 'soon').
Hi @Vsevolod Stakhov

I'm very interested - excited even! When you say "The cost of each analysis...", is that the cost of each water parameter?

JPC
 
I'm going to take a thorough look through these figures later. But, the iron figure is very much in line with my water company's 2019 report.
Yes, I was quite surprised as well. But ICP-MS shows elemental compounds, it does not show which specific chemical molecule contains that element. For example, JBL Fe test shows clear 0 for our tap water (but it shows stable chelates in fish tanks). So I can only assume that this Iron in tap water is in some insoluble compounds, e.g. rust (Fe(OH)3 + Fe2O3) or Ferrous Phosphate. The amount of P (714ug means 2.2ppm of PO4) is also higher than liquid test kits show for that water in PO4 equivalent. So I think that the tests show only soluble components while ICP-MS shows pure elemental compound. I'm not sure what methods are used in water companies, and I'm not sure I have good quality last mile pipes either...
 
Hi all,
mass-spectography analysis of the Cambridge city tap water
Very useful.
has a map in here showing the geology in the UK.
As the other have said we aren't likely to have much magnesium (Mg) in our tap water <"for geological reasons">. Some of the confusion has arisen because in the USA many of their limestones have <"undergone dolomitization">. The "dolomitization" link has the relevant maps.

The same geological reasons also applies to potassium (K), although you are more likely to get measurable levels in surface water from agricultural usage.
For now, I mix APFUK (0.05) with Chempack Iron (2% Fe, 3% Mn, 6% Mg)
That was going to be my suggestion as a <"manganese (Mn) source">.

cheers Darrel
 
That was going to be my suggestion as a <"manganese (Mn) source">.
I can definitely see the positive effect from this fertiliser as I've been using it for some months (not daily though since so far). I have linked it to Fe chelates stability but it seems that it could be related to Mn in fact. However, I'm quite concerned about unchelated Mn: it is toxic and not very stable even in 6-7 PH range. Whilst it should be stable in the original sollution due to SO4 anions providing very low PH it might not be very stable in the fish tank.
Another thing that is a bit confusing is that I have bought another similar garden ferilizer today (the same 2% Fe on EDDHA/DTPA and 6% of Mg) but the amount of Manganese is 10 times lower comparing to Chempack according to the label:
1614457750683.png

Probably, I should also send my hand-made micro to ICP-MS as well :)
 
Hi all,
Another thing that is a bit confusing is that I have bought another similar garden ferilizer today (the same 2% Fe on EDDHA/DTPA and 6% of Mg) but the amount of Manganese is 10 times lower comparing to Chempack according to the label:
My guess is that they are actually the same mix, and one of the labels has <"got lost in the powers of ten">. I don't have any reference, but I'd guess it is the "3.0%" that is wrong and it is actually 0.3% Mn.
However, I'm quite concerned about unchelated Mn:
You get a reasonable amount in some hard water, to the extent that they remove it from some tap water. I don't think that is because of toxicity issues, but because it makes the water taste bitter.

cheers Darrel
 
0.05mg/L of Mn in drinking water makes it taste foul to humans, it’s a good job plants don’t have taste buds (at least not like ours)! I target that value every micro dose 4x a week, unchelated, if there’s any chelation with Mn it’s with either Gluconate, Ascorbic, Humic or Fulvic acid in the tank when it’s dosed, maybe some unbound FeDTPA if it can, all of them advantageous and fully plant digestable. Acids in the micro Humates in the macro!

:)
 
You get a reasonable amount in some hard water, to the extent that they remove it from some tap water.
Not in our tap water definitely. 0.04ppb (not ppm) is almost zero and Mn is depleted even quicker in fish tanks (especially in more alkaline one), while other traces, such as Zn or B have tendency to accumulate. So I clearly see that Mn and (at lower degree) Cu elements are disappearing in fish tanks even when using daily EI dosing (something like 0.022ppm = 22ppb of Mn on EDTA from APFUK). But Mn in EI tap water tank is <0.0125ppb, that looks like zero to me. Even 0.13ppb (0.00013ppm) in the second aquarium is not very adequate amount. Is it possible that some aquatic plants are acting like super concentrators of this element?
 
Is it possible that some aquatic plants are acting like super concentrators of this element?

Very possibly, looking at the most basic of photosynthetic organisms Cyanobacteria who have a great affinity for Fe can’t prevent themselves uptaking Mn and will scavenge whatever is available, when it’s present at levels of 10ppm+ it can’t moderate it anymore and it becomes toxic internally to it resulting in cell disruption (this effect was seen with marine Cyano). The only way to be sure is to perform an experiment to test for loss in the water column via uptake by Fire Assay on the test plant and then measure its elemental content to measure differences.

:)
 
I’m wondering if the Mn level should be read as mg/L instead of ug/L, the Tap water has probably had some form of flocculation performed on it to remove metals such as Iron and Mn specifically because they both make it taste bad (and stain laundry), 0.04 would bring it just under the taste threshold if it was mg/L, it’s almost non existent measured in ug/L. How does the analysis compare to an official water provider report for Mn content, if it’s not stated in the report is there mention of flocculation moderation performed on the water before its piped to the tap.

:)
 
How does the analysis compare to an official water provider report for Mn content, if it’s not stated in the report is there mention of flocculation moderation performed on the water before its piped to the tap.
Here it is: Manganese ug/l: <0.9 <0.9 <0.9 (with 50ug/l as limit). Taken from https://www.cambridge-water.co.uk/media/2399/z2-cambridge-city-south-2019.pdf
I'd say that the report is quite close to what ICP-MS has found with the exception of Iron, but Iron difference might be related to the different measurement methods.
 
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