Fading from green to yellow

Strain; Blue Dream, bought from reputable seed bank

Soil in pots, Garden store variety soil

System type 1m x1m x2m (3’3" x 3’3" x 6’6") grow tent

PH of runoff or solution in reservoir? Last water 6.7

What is strength of nutrient mix? around 80% of recommended dosage


Light system, size 600W HPS

Temps; Day 25C (77F°) Night n/a, but its getting cold at night

Humidity; Day 63%, Night n/a

Ventilation system; Yes 2 fans blowing into the tent

AC, Humidifier, De-humidifier none

Co2; No

Plant is 71 days old, 25 days after 12/12 flip and started yellowing about 2 weeks ago

She gets Canna 13/14, Cannaboost and Plegron purezym every other watering with one day in between watering. The lamp is about 60cm (23 5/8") above the plant. Buds are rather small and with alot of space in between. Because of fluctuations in the pH (6.2 going in, 6.7 runoff), I’m suspecting a nute lockout. Would a good flush solve this, and does the plant look like it can be saved?
Her scrogged sister on the other hand, in the same type of soil and getting the same nutes but under cfl’s, seems to be doing fine

Any help appreciated, folks, and thanks! @Countryboyjvd1971 @bob31 @Myfriendis410 @Nug-bug @Screwauger @DoomSack @daz49 @dbrn32 @Covertgrower


I’m thinking flush until you get back to 6.2 coming out. I can’t tell from the picture but is the yellowing on old or new growth or both?


The whole plant is yellowing, but it’s worst at the bottom.

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I’m thinking nitrogen deficiency. Can you get a good close photo of leaves?

Now you can see how washed out the leaves look and how scrawny the buds are. I have another bloom fert…3-12-6…maybe that would be better, as it has a little N in it. On the other hand, the SCroG also gets the 13-14 and is deep green. Maybe the spectrum of the lamp is wrong? Think adding blue-green cfl’s might help stimulate the N?

@DieHigh55 what lights are you using?

HPS 600w but I’m not sure what the light spectrum is…it’s definitely reddish and not blueish.

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Maybe a flush and capture the last runoff for a ph and tds followed by a jolt of N. Go back to your grow nutes and mix in some with your flowering nutes and ph to 6.0.


Should I feed it right after the flush, assuming the pH is in range, or wait a few days to let it dry out a little? Baffling!:thinking:

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I would always treat a flush as a watering.


So wait a few days before adding nutes?

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@DieHigh55 hps are reddish orange in color. It mimics Autumn days during flowering. MH are bluish to use during veg. I only asked because i noticed what looks like airy buds and stretch. How close is light? I know it doesnt pertain to your original question of the leaves yellowing at this point lol

Ah, ok. So the spectrum should be right for flowering?


Lamp is about 60 cm…24 " above the plant.

I agree with the others. I’m looking at canna aqua schedule I have, it’s recommending the use of the 4 part, with just the pk13/14 as a supplement to it. I’m guessing that’s where you’re coming up with the deficiencies.


It definitely looks like nitrogen deficiency. @DieHigh55 like @dbrn32 check the schedule.

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@DieHigh55 I suggest ph low to take advantage of the change in ph up over time should make everything available to the plant.


I’m leaning toward what @DoomSack said, N issue or ph is off? The 3 on that fertilizer is N and may be too low for a vegging plant IMHO … Good luck brother, def check ph runoff, see what you come up with


I agree with you, but I also think even with the ph correct required nutrients will be absent. The canna nutes are 4 part base, and the pk is a transitional boost. Even the people that swear by the canna nutes, aren’t super impressed with the pk 13/14 even as it’s designed, let alone as a stand alone.


First conclusion: You all have been a great help. I’ve been starving the poor girl out of nitrogen, with a messed up pH to make things worse. Next feeding, after stabilising the pH, I’m gonna try a canna Terra Vega / 13-14 mix 80:20 to try and bring the N back up.
Hopefully she’ll get green again. You all have been great, a thousand thank yous. :+1: