I think a problem with water alone is that there are likely to be convection
currents which circulate the water. Therefore, it will be difficult or
impossible to obtain adequate gradients of oxygen, or other nutrients such
as you obtain if there is mud or soil as a main part of the column.
Martin Weiss wrote in message <35C71290.9EFB903F at nyhallsci.org>...
> Has anyone experience setting up Winogradsky colums using only
>water? Can you get a stratified column of anerobic bacteria grwoing in a
>column of water in the same way that you can with a column of mud? I am
>trying by building a small classical column, about 25% of the total
>volume of the column, (using mud mixed with egg or wood chips or paper)
>and the rest of the column water collected with the mud. So far, about a
>week no luck.
>>I am hoping the colonies would be more visible and perhaps we could
>sample more easily, using a thin plastic tube, used to cover fluorescent
>>Any ideas or suggestions?
>>Martin Weiss, Ph.D.
>New York Hall of Science