to answer your ? about NPK...refers to the amount of a given ingredient in your fertilizer makeup. N= Nitrogen, P= phosphorus, and K=potassium. Get yourselves something easy to use and cost efficient such as the "Flora" line of nutrients by GHE. They have a pre-printed flowchart that shows week to week how much of each to use in a gallon of water. Add some cal/mag and some molasses to the feeding and you have a really well balanced nutrient regimen that wont cost you a ton of $$.
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