Yes, contact your nute manufacturer and ask exactly how to use the nutes. They are not deceiving anybody, there is just a common misunderstanding.

If for instance your chart says 1500 ppm, that is what the plant needs over the course of one week (that is why we change the reservoir weekly), not what it needs per day!

Other than just calling your nute manufacturer to confirm, let me give you a few exercises to prove it:

Lets say you have a ten gallon rez for your plants and you filled it at 1500 per gallon and you started feeding your plants. Without topping off any water, what is your PPM tomorrow? Is it higher or lower? It's higher because the plant drank more water than nutrients (forget about the nutrients that fell out mechanically for now). Now obviously there is way too much nutrient in the water for the plant to uptake. So now let's water it down to half the strength/ppm and try again tomorrow. Same result? Keep going until the ppm neither reduces nor rises. What is the PPM and what ratio is that to your weekly total of 1500? About a 7th by any chance?

I can give a few more experiments for anyone to try if anyone wants. But what ever method you choose, let us know and I can help you make a mixture strategy, because its different based upon drain to waste and recirculating, soilless, etc..