I would have done this totally differently to everyone (again, monitoring and management/water quality not my strong suit). Would this approach have been wrong?
Microscopic membrane filtration canbe used to remove unwanted species as small as ions from a water supply. As the membrane pore size decreases, the filter becomes more efficient at removing smaller contaminants, however the use of such filters becomes less cost effective as pore size decreases.
Microfiltration (100-1000 nm pore size) is effective at removing silt, colloids and a variety of bacteria. It is commonly used in rural treatment plants with less extensive purification facilities. It is the most economical form of MMF.
Ultrafiltration (100-5 nm pore size) is highly effective at removing a greater variety of microbes, including viruses, and improving water colour. The addition of a surfactant coating also enables removal of ions from the water. It is more costly than microfiltration, but also more effective in microbe removal, which makes water more suitable for human consumption. Thus it is effective in optimising the potability of water.
Nanofiltration(0.5-5 nm pore size) is effective in purifying water when that absence of contaminants is highly important (eg in renal dialysis). It is also effective in reducing concentration of Ca2+ and Mg2+ ions in hard water at a lower cost than reverse osmosis.
Reverse osmosis is an effective method for desalination purposes. Adequate pressure is applied to overcome osmotic pressure and force water through a semi permiable membrane of 0.1 to 1 nm from a region of high solute concentration to one of low solute concentration. While it is highly effective in removing ions from water, it is a less cost efficient mechanism of achieving this purpose than smaller pore MMF.
Thus, the degree of effectiveness of various forms of MMF vary depending upon pore size and desired expenditure or equipment access. However, MMF has the capacity to be an extremely efficient, if costly, mechanism of removing contaminants as small as ions from solution.