First hydro setup PLEASE HELP!!

I have a hydro setup I made from a with a 5 gallon bucket wit a lid, I cut a round hole in the lid added a netted pot and filled it up with marbles. I put a hose running from an airpump inside the bucket of water attached to an airstone. I put the seed between the marbles in the netted pot. my plant already sprouted. With the root just touching the bubbling water. Is there any special things I need to do right now, or do I just let it grow a bit? and when Im ready for nutes, my nutes it says you should add a tablespoon to every gallon of water. now do I add 5 tablespoons because its a 5 gallon bucket? or should I only put a tablespoon in to the bucket? and how often do I add nutes? Oh and do I change water when Im ready to feed nutes again or just throw it in the same water? I dont know anything about growing hydro, this is my first expirement so any help would be great. Thanks

everything sounds good so far. you don't have to add any nutes for the first few weeks. and when you do start using them, you want to use them with a light hand. if you don't have this already, for hydro you're really going to need an accurate pH and PPM meter.

what kind of nutrients are you using?

For the veging I was planning to use the same nutes I use for my girls in soil,(VIGORO PLANT FOOD, 10-10-10) I alwalys add double what it says to make it 20-20-20.

You'll want to use hydro nutes, they are complete. And I start feeding very low-dose nutes right away.
You need to read up on reservoir management. It's all in here!

HTH