Colour at half depth The Secchi depth is: {{secchi_depth}} cm
Raise the disk to half the Secchi disk depth: {{this.halfdepth}} cm Record the Forel-Ule colour of the disk at this depth (use the colour scale on the handheld device). In addition, if it is safe to do so, take a photo of the disk in the water at this depth using the button at the bottom of this screen. The colour of the disk in the water is most similar to Forel Ule colour: To add a photo click here: Go to Step 4