Non-grinding techniques can use either GFF or membrane filters that will dissolve in the solvent. Light, temperature, water quality, and dissolved components can all have significant effects on fluorescent readings independent of the chlorophyll concentration. Temperature has an inverse relationship with fluorescence. For example, in a vertical profile, as the temperature decreases, the fluorescence will increase independent of chlorophyll concentration. Turner Designs' field and submersible instruments have the capability to automatically compensate for temperature effects.
Light history can have significant affects on the fluorescence in algal cells.
For example, at low light levels, algal cells can optimize the light uptake by pushing chloroplasts to the outer edge of the cell or by producing more chlorophyll per cell. Both of these responses can result in data increases the fluorescence signal while the algal biomass may be unchanged. To lessen the effects, opaque hose should always be used when sampling natural waters with a field fluorometer. The transport time of the water in the hose will dark-adapt cells to an extent, significantly reducing fluorescence error caused by variations in the light history of the cells. If the dissolved interfering compounds are suspected to be significant, it is worth conducting a quick study to look at the effects by comparing the fluorescence from filtered and non-filtered water samples or from noting the fluorescence signal below the photic zone and using this value as a blank.