Monthly Archives: April 2014

Can I save money on my water bill by using a rain barrel?

If the cost of the water; and the cost of the infrastructure that brings the water to “you” and takes it away when you’re done with it are considered; then, on paper, a rain barrel will pay for itself in several … Continue reading

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Designing a DIY slow sand filter: what to consider

I am writing this to summarize what has been learned here in the past 7 years of designing, building and operating small slow sand water filters – thousands of hours and hundreds of pages of documentation. The details can be … Continue reading

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A counter top slow sand water filter

This filter (we call it a “micro” filter) uses a 2 liter soft drink bottle, a rubber band a plastic straw, some plumbers putty, and coarse sand and fine sand. The fine sand on the top is .15 mm effective … Continue reading

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It is now April 11, 2014. Filter 10a, 10b, and 10c have been running steadily for about 6 weeks.  Filter 10a uses .25 mm effective size sand, filter 10b uses .15 mm effective size sand,  and filter 10c uses .20 … Continue reading

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Slow Sand filter construction

Update October 22, 2013: This filter is still working after 2 years of continuous operation. The filter has been monitored regularly, and as a result,  a potential issue with the sand has been discovered. The bottom layer is too coarse, … Continue reading

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Slow sand filter operation during dry spells

Filter 4 and 5 now have re-circulation systems installed. Both of these filters had failed miserably in April/May of this year due to lack of water throughtput, and excessive organic debris present in the input water. Since the re-circulation systems have been … Continue reading

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Biological water filtration with sand (why does it work?)

Biological sand water filtration (slow sand water filtration) works mainly because of living things we can’t see with our eyes. If water flows slowly enough through sand, it can be cleansed by these living microscopic organisms with help from gravity … Continue reading

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Roofing material and rain water harvesting

We have had water collected from a composition roof at this location tested by an EPA certified laboratory. The water passed (actually far surpassed) all epa, and local requirements for potable water purity after being run through a small slow … Continue reading

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Slow sand water filter operation and water clarity

A rudimentary test was done yesterday, October 2, 2013,  to evaluate water clarity on all of the filters running here. The filters that have the least restricted output flow also have the clearest water output. Two of the filters that have … Continue reading

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Uniformity coefficient of sand

To determine the uniformity coeffient of sand (from a chosen source):   First: Take a small sample of the sand and determine the sand grain size(wire mesh hole size opening) at which 60% of this small sample‘s weight passes through … Continue reading

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