It depends how you are using the coco. I'm using it in hempy pots and the coco never gets watered, ever. I have tubes in my pots to bypass the coco and send nutrient to the roots directly. If I was in pure coco or a coco/perlite mix in regular pots, I would water when the top couple inches dry out completely as this stimulates the roots to grow in search of water. Just make sure you rinse out your coco well before you use it or the ocean salts will kill anything planted in it or buy pre-washed coco, my coco had over 2500ppm of salts in it when I rehydrated it.
As for the nutrients, use a ppm pen and start very low for seedlings or young clones, like 100ppm for the first couple waterings and then bump it up to 300ppm and then 500ppm on the next waterings and just keep bumping up the level until you reach the desired level of nutrient. Just try to follow the manufacturers ratios for their nutrients for example my nutrients says to add 5ml/gallon of grow, micro, magnifical, and velo kelp but I went with 2ml of each to get the lower ppm dose but balanced nutrient for my young plants. I've never done the 1/4 dose or 1/2 dose thing as I want to know exactly how strong my nutrient is and a ppm pen will tell you exactly that.
