A lot of that is manufacturers' hype, eh? I use MiracleGro Potting Mix for my entire grows and those bags claim to have nutrients to support a plant for 3 months. Ignore that. I use the MG PM just like regular dirt. I water new seedlings with just plain water first 2 weeks in dirt then they get nute-water daily like everyone else from then on. Most of the time when we refer to nutes it is in reference to some additive, dry or wet, that we add to each gallon of water. You can follow package instructions or experiment. I suggest starting out at 1/4 or 1/2 of the suggested strength. Watch it from then out and adjust if needed. Chances are you won't have to adjust much or anything.
Good luck, BigSteve.