You alkalinity is not so high that you have to worry about it.You can get it down some with your regular water changes, but 3.6 is fine.
Alkalinity (meq/L)
Natural Seawater Value: 2.5 meq/L
Acceptable Range: 2.5 to 5.0 meq/L
Maintaining an appropriate alkalinity is crucial to maintaining a
healthy aquarium. A fluctuating alkalinity will lead to serious problems in maintaining an appropriate pH, as well as problems keeping calcium and magnesium levels within required ranges.