1. You are free to dose these on a schedule that is most convenient for you, every 4 days, 2x/week, or daily via a dosing pump.
2. 2-3ml per 100L (26gal) is the recommended amount for each bottle. As a starting dose, it is always best to start lower and steadily increase until you find the dose that is best for your tank. If you happen to need a higher dose, we do not recommend adding more than 5ml per 100L (26gal). Adding more does not lead to stressing your coral, instead it becomes available in excess and is removed by your filtration system.