In 10 days the hair algae will begin to dissipate. In 2.5 weeks it will be gone. Leave the MG in for another 30 days while the bacteria eat the remaining algae cells. Then pull the MG from your tank. When it dissolves, one just adds more.
Life is five years.
Its size is 1 to 4 inch and is mixed. The formula is . At this ratio it will keep the pH of the aquarium at 8.2. The reason, the acid from the bacteria is the highest at that point and reacts with the pH rock. IF you do not place the pH rock behind the TBPC, the reaction will not be complete.