Several possibilities. Green hues are likely microscopic algae while the browns could be algae or stains / color or maybe clay/silt. One way to check for clay silt is to do a settling test. One form of this test is to collect 4-5 gallons in a white bucket and allow it to set for 4-6 days. If it forms a sediment layer on the bottom and overlying water is gin clear then it was clay/sediment. If the brown hue persists it is likely stain from plant materials, but not always. Depending on the quality and particle size of your filtration system a lot of the particles including smallest algae less than 5 micrometers could be passing through your filter system.
Last edited by Bill Cody; 10/27/14 01:08 PM.
