My soil set up + question about nutrients - Feedback, please.

This is what i've decided upon for my first grow please any feedback would be great,

My soil composition 20 % miracle grow organic soil 70% lush compost that is 100% organic material that has been breaking down for 1 .5 years tomatos, eggshells , lettuce, cabbage, carrots, and chicken waste... Almost black soil that our garden flowers go crazy in 10% ( on the bottom layer ) sterilized in boiling water small fish tank pebbles to allow sufficient drainage.

as for nutrients, I was unable to find a thread that lead to an explanation of the nutrients everyone uses, Also one thing i've yet to learn about the nutrients is at what stage or week into veg or flower i begin adding them while watering or are they to be mixed with each watering from the very beginning past weedling stages?

One other thing , would it be wise to mix in sand with this soil to allow drainage and the roots an easier time to develop and at what week would be wise to transplant into a larger pot?

t - minus 1 week until i begin.

Right on for using your compost mate. I love using my compost after a couple of years. One thing to watch out for its bugs. Make sure it is all completely composted. And yes you can for sure add sand to your mix to allow drainage.. nothing wrong with that. Just make sure its sterilized. You can also use perlite too which is effective.

Nutrients.. i personally like to use supernatural nutes.. Gro terra for veg and bloom terra for flowering. Its super simple to use. 1/2 tsp per gallon in veg and then 1 tsp per gal in flower. You can feed every watering, but you will probably get some salt mineral buildup in your soil... So its best to do like feed/feed/water or feed/water/water.

Start adding nutes very slowly... Start really light in like the 2nd week of veg, and then slowly work your way up.

Good luck mate. Hope this helps.