US Long-Term Ecological Research Network

1. Filter Types:
 
a) Chlorophyll Filters:
  • GFF: These are Gelman glass fiber filters used to collect chlorophyll which is measured on a fluorometer or spectrophotometer
 
b) Nutrient Filters:
  • These are polycarbonate track-etched 0.4 um membrane filters used to filter out solids in order to measure various dissolved chemistries
 
c) TPM Filters
  • These are pre-weighed polycarbonate track-etched 0.4 um membrane filters used to measure total particulate matter. The filters are stored in individually numbered holders
 
2. Loading the filter cartridges:
 
a) Chlorophyll Filters:
 
  • GFF:
    • load the filters onto the blue filter cartridges
    • the 'puffy' side of the filter should be placed down, the uniformly-patterned side up (i.e. the 'puffy' side should be facing the flow of the water)
 
b) Nutrient Filters:
  • load the filters onto the clear filter cartridges (use blue holders if no clear holders)
  • the shiny side of the filter should be placed down (so that it faces the flow of the water)
  • each filter should be moistened with distilled water, and the filter holder should be assembled
  • once assembled, use a syringe to determine whether or not the filter is working by injecting are into the filter
  • if the filter is working, the air will rebound into the syringe, if this does not occur, check to see if there are any holes in the filter, reassemble, and repeat the process
 
c) TPM Filters:
  • load the filters onto the clear filter cartridges marked TPM 1, TPM 2, etc.
  • the shiny side of the filter should be placed down (so that it faces the flow of the water)
  • record the number of the clear plastic petri dish which originally housed the TPM filter and the corresponding filter cartridge number now containing the filter. This is done so that the pre-weighed filter is eventually placed back into its original container (eg. TPM 1 is petri dish 09-54).
 

 

Protocol ID
south_filters