Can someone give me advice

So I have 4 plants one is an auto and the other 3 are photos. One of the photos are bagseed and it’s about 3-4 weeks into flowering. I just noticed it getting pale green color and looks like a nitrogen deficiency but I don’t wanna give it nitrogen maybe a lockout but why would the other three plants be fine. Any advice would help been feeding GH trio and it’s under two marshydro 2000 temps are lights on around 78-82 lights off is 72-67.

the sick one is in the back right corner one.

Do you water all the plants the same?

HydoDan said:

Do you water all the plants the same?

Click to expand...

Yes I do each plant gets the same watering well not the auto since she’s farther along then others.

She doesn't need as much as the others.. Plants have individual needs..
What's good for one can be too much for another.. Check the weight of the pot before you water...
It should be much lighter... Your other plants are lookin good..

Codeman34 said:

So I have 4 plants one is an auto and the other 3 are photos. One of the photos are bagseed and it’s about 3-4 weeks into flowering. I just noticed it getting pale green color and looks like a nitrogen deficiency but I don’t wanna give it nitrogen maybe a lockout but why would the other three plants be fine. Any advice would help been feeding GH trio and it’s under two marshydro 2000 temps are lights on around 78-82 lights off is 72-67.

the sick one is in the back right corner one.

Click to expand...

Doesn't look like N def, mainly top leaves are affected, N should start at the bottom.
Another issue is that plant seems like it's not transpiring/drinking.
If it's an auto it's quite possible that it's receiving more light than it can handle. Pale green mag def looking plants under to strong led light is quite typical.
Either that or something with the roots.
Do you check EC in and ec of runoff?

Rocket Soul said:

Doesn't look like N def, mainly top leaves are affected, N should start at the bottom.
Another issue is that plant seems like it's not transpiring/drinking.
If it's an auto it's quite possible that it's receiving more light than it can handle. Pale green mag def looking plants under to strong led light is quite typical.
Either that or something with the roots.
Do you check EC in and ec of runoff?

Click to expand...

Yeah it’s not an auto she’s a photo bagseed the one with the problem. Sorry if I typed wrong lol. Yes I check the ppm every watering with nutes. Never higher than 450-500 but usually it’s around 350-450 ppm.

Ok so, few things I've noticed, purple stems, is the pots on floor, concrete? That might lock out Mag. as roots below 65 are troublesome. Next, ppm range in flower at week 4 should be breaching somewhere around 900. Iron is semi mobile as well as a catalyst for chlorophyll. With low PPMs your water or nutes might be lacking and now it's starting to show, as iron is used in small amounts within the plant. I personally don't feel bad about feeding nitrogen in flower IF, big if here, needed, but in very very small amounts until fixed. Another fella touched on the mag and light common run in, check into that! Believe it, or not the water schedule, among other things watering related is very real, and you can see plants become temperamental. Good luck!