yellow yellow, yellow....cant figure out why??

So ive been doing so much reading about this its fustrating.... I have 4 plants vegging for about 4.5 weeks... I had them under CFL's, but I got a t5 like 2 week ago.. Ever since then, the plants have turned really yellow.. Read about nutrient lockout and deficiency... Did flush them about a week ago and not much change. So I went ahead and went back to feeding nutes and micro nutes..

Need more help figuring it out?? Im a newbie

plants appear more yellow then pics.

id say u have N def...
or ur light isnt close enough for the bottom of the plant

Looks like N deficiency from what I see, but it could also just be from age or the strain. Give it a little bit of nutes with N and see what happens.

Nitrogen deficiency is the likely culprit. Best policy would be to confirm your soil pH to make sure it's good, then feed with an all purpose or "grow" fertilizer with high nitrogen content. It should respond in a day or two.

So its been two days since last feeding. gave them some F.F. big grow...its has about 6% Nitro....dont know if that would be enough??? Should I get something stronger???? Starting to see slight color coming back...

I would leave it alone for another day or 2 you did state that you had color coming back so I would think that what ever you did is working or starting to anyway,its best to try 1 thing at a time then you know what worked,adding more changes can add up to a dead plant. good luck peace and grow on

Nitrogen is likely to be locked out due to pH being too low. Get a accurately calibrated, digital pH meter. Flush each plant and record the runoff pH. If the pH is too low (most common) you will need to somehow get the pH up so it is available to the plant. Use a soluble form of lime if this is the case. In the unlikely event that the pH is too high, you will need to get it down by use of a acid type fertilizer or, phosphoric acid. Either way this is classic "Lockout".

so I got some good green colors coming thru.... but still have some yellowing.. I just ordered a Ph tester for the soil.... so maybe taking Carl's advice about soil.... the f.f. big grow did really help though.. but i think there might be slight lockout still.. Thanks for all the continued info...

oohhh and just picked up one of those $15 Ph meter they posted on the forum!!

feed more.

run off is pointless.

nice work. FF Grow Big has worked SUPURB for me for the couple of grows I've done so far.. Its got the perfect proportion of nutes and micronutes.. It just takes a bit of time to figure out the perfect dosage... it will work for you. just give it a week or two of scheduled and controlled feeding (about 1/2 of the recommended dosage on the bottle) and you will notice a difference... too much changing and re-configuring is not good for the plant... what i have learned is that consistency is key. oh, and pH is also key.. the pH changes when the nutes are added.

GREEN GREEN GREEN!!!! Finally had another feed about two days ago.... And green is flourishing everywhere... Thanks alot for all the help you guys.....

I guess the run off would have been pointless!!!!