Is this Nitrogen deficiency, am I underfeeding?

My plants are looking very light green, almost yellow and a lot of the fan leaves have already turned yellow and shriveled up. From what I found online, I'm thinking this is a nitrogen deficiency but I'm not sure what would be the best thing to do. I feed them every other time using the GO Box instructions and use tap water ph'd at 6-6.5.

I'm using the light feeding doses of BioThrive Bloom, CaMag+, and Bio Bud (I did not use the optional Bio Marine but I just noticed it is high in nitrogen, maybe I should add it in to help the leaf color?).
Or should I try out the heavy feeding doses and see what happens?

I've also read I could foliar feed them with ammonia to help with nitrogen but since they're 4 weeks into flowering, I'm kind of reluctant to spray them especially since I already have a nighttime humidity problem.


It's hard to tell the color bc of the HPS bulb but in the first pic you can see the difference between the tiny new leaves on top compared the the ones under them. Those the small new growth is the only thing that's green.

Complete information like strain, age, growing method, growing medium, etc & etc and a pic under normal lighting would be helpful.

The strain's White Romulan by OGRaskal.
I'm growing in 5 gal airpots with a FFOF/perlite mix. The plants just finished their fourth week in flower and since they're in scrog, i'm not really sure how to get them into normal lighting but in the pics, the darker leaves on top are normal colored and the rest is just very light green.

Everything but the leaf color seems fine, even the buds are developing nicely so I don't think it's anything but a N deficiency, so I'm thinking they just need to be fed more. Just not sure how to feed them right. Do I up the dose of all the nutes or just bloom? or just add in the bio marine to my light feeding sched?

I edited these two pics and that's the actual color of the leaves, is it N deficiency?

That would be my guess

shoegal420 said:

I edited these two pics and that's the actual color of the leaves, is it N deficiency?

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Looks like could be mites check under the leaves for little tan mites i had the same problem I thought it was heat stress or a nutrient deficiency turned out its the start of the mite infestation

K J said:

That would be my guess

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I think so too, I added the bio marine and we'll see if it makes a difference. Does it take a few days for a deficiency to start looking better or will I see a difference tomorrow if that's what it was?

idab420daily said:

Looks like could be mites check under the leaves for little tan mites i had the same problem I thought it was heat stress or a nutrient deficiency turned out its the start of the mite infestation

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I checked under a few of the leaves and don't see any mites, are they easy to spot?

All the yellow leaves will die. Look on your fert bottles and find out which one is N heavy and double that one. If leaves curl/bend to the sides pull back by a 1/4 from that. Looks like an early harvest for you. But hey, now you know next time you can act earlier..

Blindnslow said:

All the yellow leaves will die. Look on your fert bottles and find out which one is N heavy and double that one. If leaves curl/bend to the sides pull back by a 1/4 from that. Looks like an early harvest for you. But hey, now you know next time you can act earlier..

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Thanks! I doubled the N, are the light green leaves going to become darker from the extra N I fed them? How long until I see a difference so I know it really was N deficiency?
You're right, i didn't expect it to go smoothly since this is the first thing i've ever planted so at least i'll be prepared next time

Too much Nitrogen can burn your leaves too speaking from experience not guessing or hear say from me

shoegal420 said:

I edited these two pics and that's the actual color of the leaves, is it N deficiency?

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That's almost too much overall yellow for a simple N deficiency... if that makes sense.

N Deficiency usually starts on oldest leaves and burns upward through the plant. You'd have browning and dropping leaves toward the base, and then bright yellow leaves, then greenish yellow, and finally green toward the upper tips. For a whole plant to suddenly turn that yellow....something else is going on.

I think it it N related but not just simple lack of N. pH or lockout of other nutes as well. This was not much help I know

Agreed, it looks locked out from something. Perhaps burnt from salts in soil?

AimAim said:

That's almost too much overall yellow for a simple N deficiency... if that makes sense.

N Deficiency usually starts on oldest leaves and burns upward through the plant. You'd have browning and dropping leaves toward the base, and then bright yellow leaves, then greenish yellow, and finally green toward the upper tips. For a whole plant to suddenly turn that yellow....something else is going on.

I think it it N related but not just simple lack of N. pH or lockout of other nutes as well. This was not much help I know

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SnaFuu said:

Agreed, it looks locked out from something. Perhaps burnt from salts in soil?

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Well it did start from the bottom but it's been progressing for about a week and I've been trying different things to help it. I'm going to flush them tomorrow in case it is ph lockout or salt buildup in the soil.

Which is the best water to use for regular watering and feeding after I flush?
I use ph'd tap water that's been sitting out for at least a day but I think my tap water has a really high ppm and that's what could be causing the possible nute lockout so I'm wondering if using purified or distilled water is more beneficial?

Your at pk boost time but you need a little nitrogen. They probably used all the nutrients in the soil a long time ago. You should have amended the ffof with organics.

Romulan is my favorite man, wish you luck.

Dr.Pecker said:

Your at pk boost time but you need a little nitrogen. They probably used all the nutrients in the soil a long time ago. You should have amended the ffof with organics.

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Dr.Pecker said:

Romulan is my favorite man, wish you luck.

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Do you think I should just use the heavy feeding doses on the nute instructions to help the plant overall or do you think it could be lockout too?
I"m not sure if I should flush or just add more nutes

Thank you though, I've read good things about it, I'm hoping for a nice harvest

Do you have any brown spotting(necrosis)?

OR just turning yellow and drying up?

no spots, just turning yellow and drying up

shoegal420 said:

Do you think I should just use the heavy feeding doses on the nute instructions to help the plant overall or do you think it could be lockout too?
I"m not sure if I should flush or just add more nutes

Thank you though, I've read good things about it, I'm hoping for a nice harvest

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I dont use that stuff man. I take soil and make it better and just add water. no ph adjustment no nothing.