hey sivine, plants are looking good so far. just a couple comments.
you want to get that 600w light closer than 3-4 feet eventually. do it over the course of the next 2 weeks. this will help prevent stretching. i keep my 600w lights as close as 8" without any problems. move it a few inches closer to the plants every couple days over the next 2 weeks. this will give the plants time to harden off.
for your plants in soil i would put them on a feed, feed, water schedule. fox farms nutes are like most and can cause salt buildups. using a schedule like this will help you keep the plants healthy. for the ones in hydro i would feed them for a week and then give them 1-2 days of just water and then start feeding again. in your hydro setup try and keep your water temps around 65 degrees and change the reservoir once a week. this will help you avoid any problems with algae and slime. you can use frozen water bottles to help cool the res.
the plants in soil will take a little longer to dry out at this point cause they don't have a fully developed root system and aren't drinking as much water. try and let the soil get dry to around an inch below the surface before you water again. also, a few hours or the next day after a watering try and mix up the top soil to keep it from caking. this will also help the pots dry out more evenly.
if you are going to spray or mist your plants (which i don't recommend except for pest control) then do it right before your lights turn off or take your plants out from under your lights and let them completely dry before putting them back. leaving moisture on the leaves while they are under the lights can cause burn and other issues.
i feed my plants veg nutes for the first 14 days of 12/12. after day 7 i will start adding a little of my bloom nutes for a PK boost. the first few weeks your plants are still in a vegetative mode and will benefit more from MH lighting and veg nutes. also, don't just add cal/mag. wait to see if your plants start to become deficient first. run just the base nutes that you have and then look and see if you need anything. certain strain will run fine without additional cal/mag and some nutes actually have sufficient cal/mag. don't start adding things till you see what your plants need after you've jsut fed them the base nutes.
get yourself a pH/ppm meter when you can. measuring nutes by dosages (i.e. 1/4 or 1/2 strength) is just not the way it's meant to be done. being able to control the ppm of your nutrients throughout all phases of growth is the key to getting the most out of your crops.
let me know if you have any questions. here's some pics for ya. you'll notice no signs of deficiency, no yellowing leaves, no stretchy stems, etc... this is important to getting the most out of your plants. they should remain healthy throughout the entire grow. anytime you see deficiencies like yellow leaves it means they aren't healthy and therefore aren't giving all they can. don't worry about yields for now. try and keep them healthy for the entire cycle. go easy on the nutes and wait for the plants to tell you they need more. won't be long before you're growing them like this. good luck.
these are the 6 girls i have in veg right now. i've had to pull them out of the tent a few times in the last couple days cause i'm making some upgrades and swapping out a 2hp chiller for a 3hp one. these girls are 5 weeks in this pic. they've been topped and LST'd. they'll be going to flower in the next few days as soon as i finish up some plants.
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these 6 girls are day 10 of 12/12 in this pic. still under MH light and getting veg nutes with a PK boost (part B of my bloom formula).
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these are the girls i'm finishing up in flower. day 55.
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