Please help for my yellow plants

My plants were nice and green till 3 days before. Now 17th day from seed. And leaves were going to be yellow so fast in 3 days. I started with cfl lights and 15th day I see some of lower leaves going to be yellow. And I thought it was lack of light, I changed system to 400 watt MH. Light is 110 cm over plants. And in 2 days all plants lower leaves turned yellow. Also sone of upper leaves turned yellow too. I thought it may be overwatering. But they are going really bad. I will upload pictures and maybe you can help. Light burn, overwatering, underwatering, need nutrition, ph problem?
Please help and save these plants… Thank you…

Strain; White Widow.
NA Soil in pots System type? No system just in wardrobe.
PH of runoff or solution in reservoir? NA. I didnt check ph.
What is strength of nutrient mix? No nutritient yet. Indoor
Light system, size? 400watt MH.
Temps; Day, Night: 27.5 celcius, 22 celcius.
Humidity; Day, Night 50, 60.
Ventilation system; Yes 10 cm diameter fan.

All of are same… Can I heal them? I bought something for yellow leaves. It says 5 ml to 1 liter water. And spray to leaves for fast recovery. It can absorb from leaves immediately. I will try it tonight when I turn off lights. Or can I spray it while light is on. I dont want to harm leaves any more. % 1.65 nitrogen, % 1 fe, % 2.25 mg. (Spray solution formula)

Ya might try going back to the cfl’s and see what happens. They look a bit crispy.

Ok I will try it now. And what about nitrogen Spray for leaves? Would it work? Can I spray under light or at dark period?

@Donaldj @Majiktoker Please can you help me? Can these plants survive?

Mine looked like that and it was Nitrogen deficiency, although mine where a bit older. So your spray should work. I gave mine a high dose of nutes and that stopped the yellowing. The yellow never went back to green so I just pulled the leaves.

Looks like nutrient deficiency

You need to be checking your PH EVERY time you water. VERY important!

Agreed with maxheadroom looks like minor nitrogen deficiency

Either Nute burn if you just fed/or dificancy if you haven’t. or too close to your bulbs.

I had the same happen to my plants, not quite as bad. I never found out what it was, but just raised my light a bit and with my next water I gave it just water at 6.5. I did put seaweed extract in the water before the blotches, and it made then shoot up and almost touch my cfl. Hence I couldn’t tell if it was the seaweed or the heat.

The plant recovered fire, but the few leaves affected ended up getting the Chop once I seen new growth. The leave was ruining their beauty shots.

Do your pots have some holes so they can drain out good? Just wondering. Looks like these good people got you covered

Temps are pretty high too but I agree possible N deficiency

What soil are you using?

I am new member so yesterday my messages were limited. So I couldn’t answer. Thank you for all of your advices. Do you think that this plants will be good again?

@bryan Actually I checked old pictures and remember now that I changed light after yellowing started. And then it turned yellow faster in 2 days.

@MAXHeadRoom @Fever @Majiktoker @TheDuke Thank you. I am again with Cfls. I put them a bit higher. I sprayed yesterday night and tonight again. I also gave nutritions for plants with green leaves.

@Dr.DankThumb420 I also thought about it and made holes bigger 2 days ago when I just saw this yellowing start. And a bit water came from bottom. May it be about it too? Now holes are bigger and drainage is good after watering with nutritions.

@Donaldj I use again cfls and temp lowered to 23 celcius now.

@TokersHaven Just ready soil and torf mix. I dont know details. I am just beginner.

@Rugar89 I am beginner. Do I need to check Ph of water which I use for watering? Or ph of water coming under pot after watering? Or soil ph? I was using bottled water and ph is 7.4. Is it too high?

Yes they should be fine and soil ph should be 6.8

@Majiktoker Thank you. I will check it and try to stabilize at 6.8. And they are in 5 liter pots now but I want to repot them to 10 liters or more. Do you think that I must wait till they are strong again and then repot? Or will they be healthier faster if I repot them with more quality soil mix for green leave plants in bigger pots?

If it were me id wait until the problem was fixed so she doesn’t take on to much stress at once being young

I am experiencing the same issue, my girls have been in veg for about 8 weeks and my lower vegetation is starting to yellow. What should I do ? Add CalMag?

@pmaster3 Your plants are really nice and big. But that yellow leaves are just like mine. Some of them are nearly same. Same problem i think.