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How to Remove Phytoplankton

Phytoplankton are small free-living photosynthetic plants or plant-like organisms inhabiting nearly all of the world's surface waters. They are generally microscopic or barely visible in water, but cumulatively can give surface waters a green or blue-green appearance due to their large numbers. Algae and blue-green algae (cyanobacteria) species are the most common phytoplankton. Removal of phytoplankton from drinking water or from a laboratory sample of water is accomplished quite easily by a variety of filtration methods, including the use of everyday coffee filters.

Things You'll Need

2 buckets
Kitchen strainer or screen
Coffee filters

Instructions

- 1
  Collect a 2-to-5 gallon bucket full of the natural surface water from which you wish to remove phytoplankton. If your purpose is to obtain phytoplankton for study, collect water from a slow stream or pond as opposed to a crystal clear lake or river. If your intention is to create pure drinking water by removing phytoplankton, use the clearest water you can find. Ocean water and brackish water are sure to be loaded with phytoplankton species.
- 2
  Remove larger plants, animals and debris from your water sample by first passing water from one bucket through a kitchen strainer, sieve or screen into another bucket. This strained water should contain most of the phytoplankton, which is generally small enough to pass through the sieve or screen.
- 3
  Clean out and thoroughly rinse the first bucket and the strainer for use in the following step.
- 4
  Place a double coffee filter in the kitchen strainer and slowly pour the water in the bucket through the filter and into the second bucket. The coffee filters should catch and retain most of the phytoplankton from your water sample. If the filters become clogged remove and replace with clean filters. The filtered water in the bucket will be relatively free of phytoplankton.

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