Do you have ppm meter? Measure it out to normal ratings...for phosphorus at the ratio u want to give them..say you feed 1000 ppm in veg, you need very little phos if its not already in soil..so 200 ppm budswell, 300ppm K, and 500ppm N, would be great NPK mixed all together. If your adding it to the soil I would use 2-4 teaspoons per gallon on soil. If yo to use and add to water as feeding make sure you let it sit or mix it frequently (bubbler, water pump) to let the phosphorus extract to the water! Also make sure you ph is where you want it and water temp is not cold enough to stunt growth.