In September of last year a 5 gallon slow sand filter (filter 10a) was set up. The orginal post is here. Since then 2 more filters have been added to the experiment. We call them filter 10b and 10c. They have been running for about 4 months, however this winter has been very cold and all the filters here were frozen solid for nearly 45 days total. The first flow rate test this year was just done today. No dependable tests could be done in January, or February because the temps were below freezing too often.
The flow rate chart for filter 10a (from last years post) is here:
| Flow Rate Record for filter 10a. Measurements are at maximum flow (supernatent depth at max) (250 ml is about 1 cup plus 1 tablespoon) | |
|---|---|
| September 23, 2013 (start flow reg.) | .190 meters per hour (250 ml in 1min 12sec) |
| October 2, 2013 (9 days since start) | .0935 meters per hour (250 ml in 2min 27sec) |
| October 9, 2013 (16 days since start) | .0866 meters per hour (250 ml in 2min 39sec) |
| October 14, 2013 (21 days sonce start) | .0846 meters per hour (250 ml in 2min 42sec) |
| October 16, 2013 (23 days since start) | .0775 meters per hour (250 ml in 2min 57.5sec) |
| October 21, 2013 (28 days since start) | .0743 meters per hour (250 ml in 3min 5sec) |
| November 3, 2013 (41 days since start) | .0714 meters per hour (250 ml in 3min 13sec) |
| March 13, 2014 ( 170 days since start including 45 days frozen solid) | .068 meters per hour (250 ml in 3min 26sec) |
flow rates for filter 10b and 10c:
:
| Flow Rate Record for filter 10b. Measurements are at maximum flow (supernatent depth at max) (250 ml is about 1 cup plus 1 tablespoon) | |
|---|---|
| March 13, 2014 | .057 meters per hour (250 ml in 4min.) |
| Flow Rate Record for filter 10c. Measurements are at maximum flow (supernatent depth at max) (250 ml is about 1 cup plus 1 tablespoon) | |
|---|---|
| March 13, 2014 | .061 meters per hour (250 ml in 3min. 47sec.) |