Construction
The column is a rough mixture of ingredients - exact measurements are not critical. A tall glass or plastic tube (30cm long, >5cm wide) is filled one third full of pond mud, omitting any sticks, debris, air bubbles. Supplementation of ~0.25% w/w calcium carbonate and ~0.50% w/w calcium sulfate or sodium sulfate is required. Mixed in with some shredded newspaper or hay (for cellulose), ground egg-shell and egg yolk respectively are rich in these minerals. An additional anaerobic layer, this time of un-supplemented mud, brings the container to two thirds full. This is followed by water from the pond to saturate the mud and occupy half the remaining volume. The column is sealed tightly to prevent evaporation of water and incubated for several months in strong natural light.
Read more about this topic: Winogradsky Column
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