Need help . Nutrient burn or no?

Hi and thanks to ilgm for this amazing site. I have a problem with some of my plants . They are at week 6 of flowering and I’m getting yellow leafs and burns on 2 of my plants . I’m using happyfrog soil with the full ff nutrient line I have been feeding half strength every other watering. and also I am using botanicare calmag. I have a 600 watt HPS, temp between 75-79 , humidity at 45, 1 intake fan that’s controlled by temp and kicks in whenever it goes over 79F and an outtake fan that is connected to a filter then to my light to pull heat and then outside the house . It looks like nutrient burn but it’s my second grow and I’m not sure. don’t know if it is nutrient burn or deficiency please help.


What is the strength of your nutrient solution? If using an FF grow schedule it is likely nute burn from that.

FF also recommends periodic flushes to remove salts built up: when did you perform this last?

FF trio will lead the plant into a cascade of deficiencies in late flower as that is the current philosophy for growing cannabis. So you will first see yellowing leaves, then purple hues and brittle leaves.

The other thing you should be aware of is the plant is probably reducing it’s demand for nutes and the only way to monitor is to use a journal and test runoff with a TDS meter every time you water. Experienced growers tend to monitor what is coming off their media to determine what to put IN.

If you don’t have a TDS meter…you need one.

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i started the nutrients when plants where 3 weeks old… started at 250-350ppm… and went up from there all was good till last week and a half … the ppm i was feeding was 850-950 when this started. and yes i did my flushing as scheduled. last flushing was 1 week ago(i watered 1 since then with half strength ppm at 500 ) and im using the full dirty dozen… i have a tds meter but i have never tested run off. so you are saying also if i would use only the ff trio i would have deficiencys in late flowering??

and i will be watering again tomorrow with plain water and calmag then one more feeding and then im going for 1 week and half flushing with just water no calmag no nuts . so what you suggest i do other then starting to monitor my run off… will gthey turn out ok. because it is a nice yield and very frostie i don’t want to killit … :sob: . any help would be awesome and thanks for the quick response