using soil, understanding nutrients

Ive decided to go with the highly suggested 'fox farm light warrior' as my medium for my first time growing. i know i want 20-5-5 but one topic or lack of is feeding your plant in soil. Do i only water the plant assuming the soil has everything it needs?
I know the soil needs to begin around 100-250 ppm, does the ppm tell me if i need to feed it nutrients when it goes over or under?
i know the first week or two it doesnt need nutrients i mean for the later stages is ppm how i tell if its lacking nutrients? If not how will i know?

Good question my man. Your soil should tell you how long it feeds im assuming 60 to 90 days. i usually cut that in half and start using nutes in 30 to 45 days. and i start at 1/4 or 1/6 strength, depending on pot size. I grow Outdoors so it may be differant if your indoors. Never had any problems with under nutes. over nuting is very easy to do so be carefull. Dont let your PH get any higher than 6.3 and no lower than 5.3 you should be good.

thanks for that answer but im still a little lost, i cant seem to find a feeding/watering schedule on this forum or at least a rough draft on how its done on average/daily and for its later stages especially.

Are you taking about a soilless mix or actual organics.
I think light means light. Give it halfstrenght hydronutes when you plant and then full strenght or preferance
The lime in the mix is the 250ppm or whatever. do you know the properties of lime? google.
Depends on your RH and lights on/off temps and pot size. A 2 gallon pot of a light mix will need watering every 3 days in an average setup.

I use soil and dont ever check it im organic though i control it all except water

Light warrior is a seed starter. I wouldnt try to do a full grow in it by itself.

well turns out canadiens have no access to fox farm soils, which is probly for the best id feel more confident trying to find the purest form of soilless mix (0-0-0), and feed it myself.
Lets just say i have my nutrients formula ready for my plant for its 2nd and 3rd week after sprouting how do i go about dropping the formula on her (but especially in her later stages), do i pour it on the stem or do i pour all around the dirt, i dont know how the roots 'absorb' system works so if someone can let me in on some of that knowledge id appreciate it thanks for all the help so far