It depends on several factors. Mainly your medium and how much of the nutrients are being added, and how often you water. Personally, I have never, and will never, feed a plant every time I water it. I try to mimic nature as much as possible. Even in coco.. I dont feed every watering.. Coco is excellent at retaining nutrients so it's not necessary. I've always used a feed/plain water/plain water/feed schedule. Every one is different. You find to find what works for you and your plants. Watch and listen to the plants.. They will tell you if and when they need feeding. Imagine being thirsty and just wanting a little water... But every time someone brought you water, they brought you a full meal with it. And they made you eat that meal every time, whether you want or not. Bottled nutes are immediately available to the plant. It's like giving them an IV full of nutrients. Needed or not. Just something to think about..