The five gallon slow sand filter experiment, mentioned in September of last year (2013) is still in progress. Due to some unforeseen issues, the EPA tests cannot be done as of yet. We will attempt to start some field tests on the three filters (filter 10a, 10b, and 10c) as time permits. These filters are still in the process of recovering from being totally frozen this winter. Until about early March, there was no water flowing through them.
A summary of what we have observed so far:
These filters will work, but there are some serious issues.
It is necessary to keep the flow rate very, very slow; much like a dripping faucet.
They are very easily disrupted if moved or bumped even slightly as the biofilm seal between the sand and the container may be broken easily – the sand and water in the bucket is so heavy it causes the bucket to flex if even moved slightly. As a result, the output is bad for about a week.
They are inferior to the much larger 55 gallon filters we have running here, but most certainly better than nothing.
As an experiment, they appear to “work” to filter out some turbidity, and we have noted what appears to be some removal of biological contamination. The water that comes out of the roof water diverter and is poured into the top of these little filters is improved by running through them.
If anyone reading this has conflicting information, please post it here in the comments section below.