Pond Boss Forums POND CONSTRUCTION Creating habitat Structure in our new pond

Depending on goals (and subject to them) , structure at all depths is a good idea. Even in the south deep structure will be used for many months out of the year (just not when DO is low). Structure below the thermocline will not be used during the period of low DO.
Avoid long term used of CUSO4 - only in emergency conditions with full knowledge of what to do and the consequences.