I would not use alum unless you first do some routine dissolved phosphorus (soluable P or ortho P) tests as baseline information to determine if ortho P is the problem that could be reduced with an alum treatment. Total phos tests measure all phosphorus in the water column, dissolved and all that is bound in the living and dead organics in the sample which can amount to more than the ortho P. Bound P does not grow any plants until it is recycled and becomes available as ortho P.
I also think it would be informative to know what the phytoplankton density is 2 to 3 ft below ice, pre ice cover and during mid winter. This will tell you the potential for loss of DO when light penetration becomes limited to the point phytoplankton is dead & decomposing.
Last edited by Bill Cody; 11/20/13 09:02 PM.
