I redid the experiment. I couldn’t wait to get the new vials. I needed to know NOW!
Phosphate before silica: 4ppb
Put silica in syringe and used my 0.22um filter. Added a drop directly into the 2L test beaker.
Silica flashed 2.00ppm. I wonder why? I think the drop was larger because of the strainer. I estimated the Si to be about 3ppm based on the color. It was a nice dark blue color.
Tested PO4 after: 19ppb
0.046ppm increase.
This experiment would have been better if I knew the exact Si concentration. I can redo it again when I get the new vials.
Phosphate before silica: 4ppb
Put silica in syringe and used my 0.22um filter. Added a drop directly into the 2L test beaker.
Silica flashed 2.00ppm. I wonder why? I think the drop was larger because of the strainer. I estimated the Si to be about 3ppm based on the color. It was a nice dark blue color.
Tested PO4 after: 19ppb
0.046ppm increase.
This experiment would have been better if I knew the exact Si concentration. I can redo it again when I get the new vials.