Vsevolod Stakhov
Member
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.
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...
Element | Dim | Tap water | Tap water tank (EI) | 50/50 RO/Tap tank (EI) | 50/50 Tank after 3x 50% changes |
Li | ug/l | 7,9 | 8 | 4,5 | 4,1 |
Be | ug/l | < 0,03 | < 0,03 | 32 | < 0,03 |
B | ug/l | 25 | 120 | 60 | 47 |
Na | mg/l | 11 | 19 | 9,9 | 8,1 |
Mg | mg/l | 4,2 | 10 | 11 | 7,7 |
Al | ug/l | < 0,25 | < 0,25 | < 0,25 | < 0,25 |
Si | ug/l | - | - | - | - |
P | ug/l | 740 | 1160 | 1240 | 340 |
S | mg/l | - | - | - | - |
Cl | mg/l | 24 | 30 | 14 | 15 |
K | mg/l | 2,1 | 27 | 43 | 12 |
Ca | mg/l | 110 | 110 | 52 | 52 |
Ti | ug/l | 0,17 | 0,4 | 0,53 | 0,2 |
V | ug/l | 0,089 | 0,25 | 0,048 | 0,059 |
Cr | ug/l | 0,25 | 0,7 | 0,17 | 0,096 |
Mn | ug/l | 0,04 | < 0,0125 | 0,13 | 0,024 |
Fe | ug/l | 180 | 340 | 250 | 110 |
Co | ug/l | 0,16 | 0,82 | 0,57 | 0,21 |
Ni | ug/l | 3 | 4 | 5,1 | 1,8 |
Cu | ug/l | 21 | 14 | 16 | 11 |
Zn | ug/l | 3,2 | 45 | 93 | 41 |
Ga | ug/l | 0,0064 | 13 | 11 | 0,0049 |
Ge | ug/l | 0,08 | 0,2 | 0,18 | 61 |
As | ug/l | 0,22 | 0,72 | 0,26 | 0,12 |
Se | ug/l | 0,63 | 0,42 | < 0,2 | < 0,2 |
Br | ug/l | - | - | - | - |
Rb | ug/l | 1,6 | 11 | 13 | 4,7 |
Sr | ug/l | 430 | 450 | 180 | 190 |
Zr | ug/l | < 0,05 | 0,12 | < 0,05 | < 0,05 |
Nb | ug/l | 0,0085 | 25 | 11 | 0,0048 |
Mo | ug/l | 0,35 | 1,2 | 5,4 | 2,9 |
Ag | ug/l | 0,047 | 0,14 | 0,064 | 0,0077 |
Cd | ug/l | 0,003 | 0,0043 | 0,0065 | 0,0032 |
Sn | ug/l | < 0,003 | 0,15 | 0,097 | 0,012 |
Sb | ug/l | 0,066 | 0,11 | 0,12 | 0,065 |
Te | ug/l | 0,0094 | 0,016 | 0,02 | 0,011 |
I | ug/l | 2,5 | 0,32 | 0,3 | 0,83 |
Cs | ug/l | 0,011 | 0,037 | 0,038 | 0,013 |
Ba | ug/l | 61 | 50 | 12 | 14 |
La | ug/l | < 0,0005 | < 0,0005 | 0,0014 | < 0,0005 |
Ce | ug/l | < 0,0005 | 0,0014 | 0,019 | < 0,0005 |
Pr | ug/l | < 0,0005 | 0,0034 | 0,0079 | < 0,0005 |
Nd | ug/l | < 0,0025 | < 0,0025 | 0,0059 | < 0,0025 |
Sm | ug/l | 0,00085 | 0,0069 | 0,011 | 0,0023 |
Eu | ug/l | 0,0071 | 0,0079 | 0,0039 | 3 |
Gd | ug/l | < 0,0005 | 0,0057 | 0,0083 | 0,0015 |
Dy | ug/l | < 0,0005 | 0,0075 | 0,011 | 0,0014 |
Ho | ug/l | < 0,0005 | 0,0011 | 0,0019 | < 0,0005 |
Er | ug/l | < 0,0005 | < 0,0005 | 0,0035 | < 0,0005 |
Tm | ug/l | < 0,0005 | < 0,0005 | 0,0009 | < 0,0005 |
Yb | ug/l | < 0,0005 | 0,0068 | 0,013 | 0,0031 |
Hf | ug/l | 0.095 | 0,19 | 0,11 | 0,06 |
Ta | ug/l | 0,0028 | 0,0046 | 0,0029 | < 0,0025 |
W | ug/l | < 0,0025 | 0,0068 | 0,011 | 0,0062 |
Hg | ug/l | < 0,025 | < 0,025 | < 0,025 | < 0,025 |
Tl | ug/l | 0,01 | 0,0094 | 0,0097 | 0,0059 |
Pb | ug/l | 0,094 | < 0,025 | < 0,025 | < 0,025 |
Th | ug/l | 0,017 | 0,067 | 0,029 | 0,0095 |
U | ug/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...