Nutrient feeding and frequency

I have read a lot about how much and what type of nutrients to use at different stages of marijuana growing, so you would think I had my head wrapped around feeding my plants. My plants are currently in the seedling stage and I am feeding with vigoro 10:10:10 nutrients. I have a tds meter and feed at 100 ppm. I will slowly increase this towards the vegetative stage and switch to a higher nitrogen nutrient. The one thing that confuses me is the frequency of feeding. I can't seem to find much of any info on how often to feed. I have my seedlings in 1 inch rock wool at the moment and they are about to move into 4x4 rock wool cubes. They are 7-10 days old and are on their 2nd to 3rd set of leaves. I have been watering once a day and feeding every other watering. I have been considering changing the frequency of feeding nutrients to every watering. Would this give my plants the same amount of nutrients as feeding 200 ppm every other watering? I am also worried about nutrients building up in the soil. Would feeding every other watering prevent nutrient build up? This is my first grow so I want to be slightly conservative on feeding, but still want my plants to get the nutrients they need.

Anytime 1hit , sounds good..