11-29-2013, 04:47 PM
Interesting thought here: There is some consideration given to whether hyper cleanliness can cause allergies. Getting certain childhood diseases is a necessary and desirable rite of passage. Are we forgetting that our ancestors drank out of mud puddles? Granted a lot of them died from it, but the idea that the water must be absolutely free of anything growing may be excessive as well as unrealistic.
Anyone familiar with slow sand filters? They are in some ways similar to a pool filter in that they are arranged so the water filters downward through a column of sand. However they are not "cleaned" the way such filters usually are, by back-flushing. They are designed to have a slow rate of water flow down through them. This of course physically captures many solids. However it is the biological activity in the first couple of inches of sand that does the real work. Far from creating a sterile environment, the goal is to create a microscopic wild kingdom where all the problematic stuff lives fast and dies young before it exits the filter at the bottom. In some respects it is a mini-leach field in a bath tub. You never back-flush the top layer in the classic sense but instead do something called wet harrowing, draining off the couple of inches of water that are normally maintained above the top of the sand as you stir up the top couple of inches of sand. The goal is to keep the organisms that live in the top layers of sand in the right place and not disrupt the layering too much, but still get rid of the solids that are obstructing flow.
Or buy a couple of $30 filters.
Anyone familiar with slow sand filters? They are in some ways similar to a pool filter in that they are arranged so the water filters downward through a column of sand. However they are not "cleaned" the way such filters usually are, by back-flushing. They are designed to have a slow rate of water flow down through them. This of course physically captures many solids. However it is the biological activity in the first couple of inches of sand that does the real work. Far from creating a sterile environment, the goal is to create a microscopic wild kingdom where all the problematic stuff lives fast and dies young before it exits the filter at the bottom. In some respects it is a mini-leach field in a bath tub. You never back-flush the top layer in the classic sense but instead do something called wet harrowing, draining off the couple of inches of water that are normally maintained above the top of the sand as you stir up the top couple of inches of sand. The goal is to keep the organisms that live in the top layers of sand in the right place and not disrupt the layering too much, but still get rid of the solids that are obstructing flow.
Or buy a couple of $30 filters.