Help seedlings turning yellow (pics)

[kmlzbmr]

Hi this is my first grow just need some help. I am growing Ice wreck on the left and Sour Diesel on the right. Germinated 15 days ago, planted in medium 2 days later they grew fine cotyledons and first actual leafs grew green but since the last 5 days or so leaves are turning yellow and dead at the tips seem to be more yellow in the grooves of the leaf.
Enviroment:
top fed ------------ 12.5 L of water 2 air stones in 5 Gallon tub
im using general hydroponic flora series nutrients. I put nutrients in when i saw the first leaves, im using just about a teaspoon of each of the 3 nute bottles: they recommend 33ml per 100L for seedlings so basically 33% of 12.5L = 4.125 ml, teaspoon is 5ml so im using just under a teaspoon , and 2 days ago i flushed out the water and put in about 3/5 of a teaspoon thinking i put in too much the first time but doesent seem to be making a difference.
Ligts are 380W LED had them about 16 inches from plants about 2 days ago moved them to about 2 feet
temp was 28celcius now 21-22c after i moved the lights up 2 days ago i also put in a exhaust fan 2 days ago thinking this may all help.
water was also high PH originally as i had no ph meter, when i flushed 2 days ago i put in ph water and ph'd again after nutes to 5.6

Any help is appreciated thanks.
2 days ago before i moved light up and adjusted water they still look the same:

5 days ago they were green with a bit of yellow

 

[Stealthboat]

They are too tiny for nutes yet, I would just remove all nutes until there are at least 4 solid sets of leaves on them. Raising your humidity would help also. You made the right choice moving the LED's up.

 

[kmlzbmr]

They are too tiny for nutes yet, I would just remove all nutes until there are at least 4 solid sets of leaves on them. Raising your humidity would help also. You made the right choice moving the LED's up.

OK thanks I will try and flush the system again and see if it helps, but is it progressing as in height and vegetation on schedule givin the plants are 2.5 weeks since germination ?

 

[RWTucker]

OK thanks I will try and flush the system again and see if it helps, but is it progressing as in height and vegetation on schedule givin the plants are 2.5 weeks since germination ?

They're not too far off. Remember that it's growing as big or bigger under the soil. The plant has two main parts: what you can see (foliage) and what you can't (roots).

So this part is the hardest, because you want to speed it up, but it needs to go slow at first so it can develop. That's why Stealthboat responded that nutes aren't necessary. Treat them like you would a human baby: gently. You don't pump a baby full of steroids to get it ripped and enter it in the squat competition, you let it grow at its own pace.

You're doing great! You'll have buds in no time.

 

[Stealthboat]

OK thanks I will try and flush the system again and see if it helps, but is it progressing as in height and vegetation on schedule givin the plants are 2.5 weeks since germination ?

It's fine so far. If they stretch too much move the light a little closer.

 

[kmlzbmr]

It's fine so far. If they stretch too much move the light a little closer.

Thanks guys, I flushed the water and put very little nutes in now like that they are getting more leaves, theleaves that were yellow are still yellow but now im seeing new leaves growing at least, it felt like they were stuck for a while i think the flush helped. but my PH is constantly going up could it be the cocco rocks causing this? I heard you are supposed to soak the rocks before using them

 

[Stealthboat]

Glad they are doing better now. I have no idea about the coco rocks. Just keep that ph stable and all will be well