Really thank you for that last response, very helpfull, i have given them all 1/2 strenght bio nutes yesterday and made sure i only watered lightly with about 1/2 a litre through each 4L pot, they definatly showed signs of improvment since then greening up and lifting up instead of drooping down, if you compare my last pics to my origional pics in first post you can see they definatly like it, i am now wondering how i should proceed now that im pretty sure they are starved, should i do a 1 of big hit with nutes or just start at full strength or keep feeding at 1/2 strength, the soil is 1 3rd perlite and 1 1/3 peat moss and 1 3rd potting mix so i guess theres not much in it, should i water lightly again today or wait a day or too? Soil is lightly moist and can see roots coming out the bottom of the pot
Well, I love to experiment, so what I would do is pick a plant and give it a full dose of nutrients, see what happens. They are so tender and young right now that I don't know if a full dose of ferts is what they need. Plants that small don't need a total drench, either, and this confuses a lot of people, especially right after transplant, they aren't sure how much water to give because they are using a bigger pot now. I went from 16oz cups to 7 gallon fabric pots, so that was kind of challenging at first.
The potting mix, what brand is it? It's probably mostly peat as well, so in reality you're probably running 1/3rd perlite and 2/3rd peat. In other words, very little nutrients to speak of in the mix.
I think the only way, the safest way to know for sure, is to use one as a guinea pig. You probably wouldn't hurt it too bad. Another thing you should consider, is that it's easy to rush things when growing. Plants don't seem to grow an inch for what seems like forever, but the next thing you know you got buds. Patience is key. It will take 3-4 days until you see any kind of result. When things aren't 100%, like now, that can make a day feel like a month, so be mindful of the time the plants have had to respond to what you've given/not given to them. I'm guilt of it myself, going back into the grow room 2 hours later expecting something different.
If the soil is lightly moist, don't water yet. You could get away with it in later stages of growth, probably even this stage, but their root systems are still establishing themselves, and you want the roots to go out in search of nutrients and water. That's what i was referring to when I mentioned the possibility that after the transplant, the roots weren't able to bridge the gap. It's a real thing. If your plants aren't seated properly, from being overly careful transplanting, their roots will stay within the rootball they had originally.
Are you adjusting the pH of the water you feed them? Are you adjusting the pH after you mix in nutrients? Once won't hurt, but if occurs over and over, a wrong pH of the water will change the pH of your soil. I add my nutrients, mix, test, then add the proper amount of ph up or down until I reach 6.5. After a grow, you'll know how much you need to add of ph down, or ph up, and ya only have to check the pH every now and then, in case your water provider flubbed up, which happens. I don't suggest such complacency though...but it's better than not testing at all. Meters are cheap, every Marijuana plant deserves one.