my plant is turning a yellowish light green?

was just wondering i have 3 plants i have 4 f40 bulbs going and a fan on them all. the temp is from 75-80 and the humd. is usually35-40 i keep the light on 24 hrs. two plants are turning a neon yellow with a hint of green but still look strong the other is dark green but droopy i water when the soil cracks i feed every other watering with m.g. 1/4 teaspoon i no the soil i bought was from wal-mart and had food in it? am i over doin it and they are turning yellow and the dark one is it supposed to droop like that?????
any help would be much appreciated
thank you
i am adding pics
or am i just overreacting?
first grow and am really enjoying maybe i am fussing over them to much? any info would be appreciated when do you think i should 12-12 them to force them to flower
thank you
again

Looks like overwatering. That's a big pot, and roots go deep. Check the weight of it before you water. Or check deeper, at least a couple inches down.

needs nitrogen

dont be giving it MG the whole time.

Yahweh, why do yo say nitro? Could be many things and to say nitro could throw this poor grower off.


The correct thing to do is get a ppm pen. Test the runoff from the pot. The water comming out the bottom.

You will really have to do that unless you just want to guess.

you could do that too and flush. but i will explain that in a sec.

get the ppm of the runoff. What is it? You plant should not be eating that much, it should be at say 600ppm at the highest right now. Maybe even as low as 400. If it is over 600 then flush! if it is way low, like 100 or so, then you need to feed.

If you need to feed, then bring the h2o to 400-600ppm with the ppm pen and then water it a good amount untill the runoff is the same as is going into it. You may want to check the pH this way too but it looks like you pH is in check for the most part besides those spots on lower leaves.

If there is now way whatsoever to get a ppm pen, then you should flush with distilled water. Use 3x the volume of the pot. 1 gallon pot use 3 gallons of water. After you flush it (we now hope the water and soil are at 0ppm but without a pen you gotta just hope its there) you gotta feed. Bring it to what is says on the bottle, if you don't have a teaspoon and tablespoon then mabye growing isnt for you. haha.

anyways, bring it to the correct nute level, give the plant a good amount to make sure the nutes get everywhere and congrats! your done!

Now you should give it just plain water or water and some paranaha, and let the plant eat the nutes, again, you should have a ppm pen to see how much it has eaten and when it needs more, or you gotta guess again. Bring the h20 up with nutes, feed, water, water, water, feed, etc, etc,

hope that helps.

oh yeah, and the first one is way way drowned. Ease up, wait till the soil is pretty dry, no need for it to go bone dry and risk killing your plant, but make sure the top of the soil is dry, again, if you cant tell, then you are best off with a meter and ones for wet/dryness of soil are very cheap and are available at CVS wallmart and eveywhere pretty much. When I say Feed, water,water,water, feed, That should take you a week, 10 days or maybe even up to 2 weeks depending on how big your plants are and what size pots they are in.

Experience is key. Even if these don't turn out and I really hope they do, everyone should keep trying, it has taken me forever to get a harvest, but now you know