Roofwater harvesting using slow sand filtration

Water Clarity

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These images were taken using a small low power red laser. The amount of color in the red line is an indication of the clarity of the water - more color visible means less clarity and higher turbidity.
Please note, however, this is NOT a scientific turbidity test - it is merely to be used as a general indication of improvement in water quality.
This method is used when the water from the filter becomes so clear
that it is difficult to tell the difference between perfectly clear water,
and filter output water by just "looking" at two samples.
New information on filter 4 water clarity as of April 15 2012:
the two images below were taken with a cannon EOS Rebel T2i on manual settings:
exposure time 15 seconds, F8.0, iso 100, using manual focus.
Both glass containers are the same type and the laser is from the same source in both cases.
filter 4 water clarity april 2012
Filter 4 water clarity as of April 15 2012
well water clarity april 2012
Well water clarity as of April 15 2012
(this is the water we use as potable from our 130 foot deep drilled well - the water is of very high quality

pre_filter water clarity april 2012
pre-filter water as of April 15 2012
A is filter 4 output, B is well water, C is pre_filter
Which one is prefilter, well water, and filter 4 water?

Information on filter 1 below:
Water from the filter (filter 1)
Water from the diverter before filtering - high turbidity
Water from a deep well that has been
filtered by a 10 stage commercial filter

Water from the cistern shown on this site
water samples
Can you tell which sample came from the diverter and which one came from the filter?