Go by Canna. Their feed charts give you a range of how to feed, and what you pick in that range is dependent on what your plants need at the time. Yes they leave a little bit for the user to figure out but steer you in the right direction. There is no perfect feed chart, you need to learn you plants. What "since 1991" said is a pretty simple example of why you might not always want to follow a feed chart to the tee. Plants drink more when it's hot, less when it's not.
And don't use Dutch Master (DM) for a little while. They have been purchased by Fuji Films (no BS) and are discontinuing all product lines. They will be reintroducing a new cannabis specific line soon under the Dutch Master name. DM did make good quality stuff, but wait since all their current products will be obsolete by year end. Most wholesalers have remaining DM products on clearance.