Nutrient burn or nutrient deficient?

I’ve had some trouble with this plant from the start, but this spotting is new. I can’t tell if it’s too much or too little of a specific nutrient. Looks like my phosphorus test is very low, but also nitrogen might be too high? I’m feeding the fox farms vegetation stage feed, 3tsp per gallon every 3 or 4 days. Plant is just over 4 weeks old and is an autoflower,also is NOT flowering yet :confused:

I also think it’s odd that sometimes it has no scent, sometimes the whole house is exploding with smell, and others i barely get a hint when i’m right next to the tent.

Looks like a deficiency. Possibly potassium.

What’s your pH. Have you flushed lately??

I’m not sure what that is, so definitely haven’t done it. Heavy watering with no nutrients i’m guessing?

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Let me tag some folks who use the fox farm nutes. Every 3 days seems excessive to me but not sure. @Whodat66 @raustin @Oldstoner @Countryboyjvd1971

Do you test your pH? Ppm?

Cannot tell due to grow light. Use neutral lighting for plant nutrient issues. :wink:

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Thanks @Drillbit. You say 3tsp, which is half strength of what is recommended, and probably non enough of what the plant needs at 4 weeks.

Every 3 days with no plain ph’d water in between I think is the other part of the problem. Half strength every feeding does not equate to full strength.

Luckily you are at the point where t calls for a flush, so you can start over.


I do use Foxfarm nutes and it is critical to do those scheduled flushes, otherwise you get nute lock which is what it looks like you have. I recommend you do a flush with Sledgehammer and then replenish the nutrients at full strength.

Half strength every three days is a lot of nutes. You really should be watering with Ph water in between feedings. So do a water, water, feed schedule instead.


Mine look like that myself and I know I tend to over water. So that is my gues which is the same as yours. I just wrote myself a bunch of notes reminding me to chill out with my watering. Good luck everyone have a nice morning

Thank you for the advice. I am going to try what you wrote. I use Fox Farm myself. And I noticed some of the same problems our fellow member showed on this thread.
If you don’t mind me asking when you feed and if it comes out to once a week instead of twice, do you use the full strength for that one feed for the week? Or do you still keep it half strength even though you’re giving nutrients once a week? I hope that made sense. Thank you
I noticed a few tips got burnt myself when I fed them half strength for the first time. I also have to do my flushes. Thank you for the advice. Have a nice morning

It really depends on your lighting. When I was using the blurple light I only fed at half strength once a week and that was enough. Now that I use a QB I feed full strength twice a week and I still need to add Cal Mag to the mix. So you really need to feel it out. I like to feed till I see the tips start to burn and then I back off the nutes just a bit. That gives me the perfect dosing. Try to read the plants, they’ll tell you what they need.


If I can try to make it simple, your plants are almost to the stage of you soaking them to the point of run-off. A pic of the whole plant would help n with diagnosis, and a better pic of the leaf in question. Post them separately and we can zoom in easier.

Your soil has some nutrients in it, but you also have to ensure you are right at that 6.5 pH to make the best use of them.

As an example - If I add nutrients and they have a ppm of 1000, my run-off can be higher than that based on nutes already in the soil - like 1200-1300.

On the second watering with no nutes, after the pot feels light and needs water, my run-off will be in the 600-800 range. This means there are still nutes in the soil, but that the roots will have to grow to search them out.


Yep 95% of all my issues have been ph related or pests . Speaking of pests how is everyone loving all the knats from the eztra rain ? It has been a struggle here lately


All of it makes sense to me. Thank you for taking the time and everyone for letting me ask the question. I appreciate the help. Thank you for the advice I’m going to proceed accordingly. Have a nice morning everyone.

Pest are so annoying. Gnats yeah. Why they come after rain? Ive seen 2 years in a row thousands of them crawling on greenhouse want to get in to my precious plants. And thats tha story how i become massmurderer. :face_with_hand_over_mouth: