The best way to know how much to drip daily is to test your parameters often (daily if possible). Your alk and cal levels will let you know how much is needed. It's basically dose and test, dose and test until you get it dialed in to match the uptake of your system. Start with low amounts and slowly work your way up to ensure you're not dosing too much too quickly which would cause big, potentially harmful swings. Fully saturated kalk has a pH of around 12 so you could test pH to see how much you need to mix per gallon to reach that level. Also, it is best to drip kalk at night when your lights are off to help keep the overall pH of the system more stable.