ALK Sky High!!!!

[banditpowdercoat]

just did water samples on my tanks., All are good except Alk on the 150. The Salfert test show's 16
Params are

Sg 1.025
PH 8.3
Po4 Undetectable
Ca 345
Mg 1200
Alk 16+

I acctually did not get a reading with one syringe, It took 3 drops of the 2nd syringe to get the Alk to change color. My other tanks are hovering around 8-8.3 so I know the kit is OK. I checked it twice, same reading too. What gives? Can it really be that high? what brings Alk down?