Too much or not enough: nute advice please

Thanks for all of the expertise here. I’m about 50 days into this grow (my second with the current setup). Things are moving along pretty well, but as flowering develops, some leaves are showing signs of stress or deficiency. Front and rear right are Runtz auto, rear left is Skywalker OG auto. Any insights from experienced growers appreciated.

They are in ffof. After about 30 days, I started adding the ff trio at less than 50% recommended dosage plus ff cal mag. My sense was that the largest plant especially was showing some deficiencies. I’ve added nutes every other watering since day 30, so they’ve had three rounds of additives (except the smaller Runtz, still waiting to dry out for its next dose.) Using local spring water which is around 6.35 ph. Recently turned the light (s33) up to 100%, 19-20” above tallest buds. Maybe pushing things at @1000 ppfd?

Should I hold off adding nutes to the one plant that is somewhat darker green (back right in group pic - the front and the rear right plant are the same type, though look quite different)? Watering to run-off and then letting them dry, a three to five day cycle. Thanks for any insights.

hows the PH of both your water going in and coming out of the pot? just by looking at it and taking a guess i would water it with some epsom salt and make sure ph is proper

Possible calcium deficiency. Low PH can cause this.

terpedup83 said:

hows the PH of both your water going in and coming out of the pot? just by looking at it and taking a guess i would water it with some epsom salt and make sure ph is proper

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Thanks for the reply. Ph has been @6.4. I have not tested runoff, but i can next time out!

DeadHeadX said:

Thanks for the reply. Ph has been @6.4. I have not tested runoff, but i can next time out!

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Don’t bother testing runoff pH.

hotrodharley said:

Don’t bother testing runoff pH.

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why not?

As long as ph going in is correct your good. PH out can change depending on a lot of variables and usually does not matter.

Still a noob at visuals. But from what I can see
back right has "the claw" leaf tips curling down which is a sign of to much nitrogen.
back left is a hard one, But its showing signs of lack of calcium( be careful because that does not necessarily mean add calcium) It could be a lockout from to much of another nutrient or PH has gone out of wack, I have also seen too much light cause it.
front plant has burnt tips that are NOT curling. which is a lack of P or K not sure which one, This is usually solved with a bloom booster which has both. If they were curling then its usually nutrient burn.

Chow13 said:

As long as ph going in is correct your good. PH out can change depending on a lot of variables and usually does not matter.

Still a noob at visuals. But from what I can see
back right has "the claw" leaf tips curling down which is a sign of to much nitrogen.
back left is a hard one, But its showing signs of lack of calcium( be careful because that does not necessarily mean add calcium) It could be a lockout from to much of another nutrient or PH has gone out of wack, I have also seen too much light cause it.
front plant has burnt tips that are NOT curling. which is a lack of P or K not sure which one, This is usually solved with a bloom booster which has both. If they were curling then its usually nutrient burn.

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Thanks. I notice that back right too, though that plant has had minimal nutes aside from the ff soil. Maybe I will add only water to that plant for the time being?

DeadHeadX said:

Thanks. I notice that back right too, though that plant has had minimal nutes aside from the ff soil. Maybe I will add only water to that plant for the time being?

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Most of your problems seem to be in the new growth and not the bottom leaves. I would guess if it isnt overwatering its overfeeding..
Really sux when 3 plants being treated the same are all telling you different things. Good luck

Here’s the most troubled plant now. I gave a couple rounds of plain water, but the problem has spread upwards. I did feed it again in the last watering, very light dose simply trying to add some phosphorous and cal mag as I poke at potential issues. I also backed off the light and the heat a little bit, but doesn’t seem to help. Getting a bit of fade on the other two also, though perhaps some of that is natural at this stage? Insights or advice appreciated! Local spring water with a ph of @6.35.

Room temperature and humidity?
I'd guess low ph. Day 50 with a peat mix and adding feed to acidify already acidic water.
Unless 6.3 is with feed.

furnz said:

Room temperature and humidity?
I'd guess low ph. Day 50 with a peat mix and adding feed to acidify already acidic water.
Unless 6.3 is with feed.

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Thanks. 6.3 is out of the spring, before feed. Room temp is 72-77f or so. Tent cools off, heater kicks in, etc. 62-65f with lights out, though I’ve been running lights 20 hours a day to help compensate for heat (prior to getting the little heater.) Humidity currently maxing at 47%. I’ve been steadily dropping it as they’ve flowered

Definitely low ph. With feed you're probably down to low 5's.
With peat mixes I like to raise the ph of the nutrient solution to counter the peat acidifying as it breaks down.

You didn't say humidity but running a heater I'd say it's probably dry and could be causing your plants to take up too much nutrients(high VPD).
You know the ppm of what you feed?

If your ph is at 6.3 straight from spring .Them your having a low ph problem . Anytime you add nutes to water it lowers the ph of feeding so your plant won't be able to utilize feeding due to been at wrong ph . Feeding more just compounds the problem .Over watering because your trying to correct something . With soil hurt plants take a while to respond so patience is also key in correcting things

Humidity is sitting at 47%. I’ve been lowering it steadily as they moved into flower. Low ph makes sense. Grrr. The healthiest plant has gotten the most nutes, though perhaps she’s just a superior phenome. I’m pretty confident over watering is not the problem - I’ve been really careful on that front, allowing them to get pretty dry/light between waterings.

Suggestions for next move? I’m planning on straight water for at least the next round. But should I proceed with nutrients and some ph up? Silly of me not to test the boosted water, but I didn’t. Was feeling great about making trips to the spring for nice clean water too!

I would try feeding 550ish ppm(500scale) or as close as you can and if possible, adjust that solution to a ph of 6.5.
Tigerbloom is high in phosphorus and better for tomatoes than cannabis.
It does work but isn't ideal imo.

furnz said:

I would try feeding 550ish ppm(500scale) or as close as you can and if possible, adjust that solution to a ph of 6.5.
Tigerbloom is high in phosphorus and better for tomatoes than cannabis.
It does work but isn't ideal imo.

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Thanks. I’m already researching ff alternatives for my next grow. I really appreciate the advice.

Just to throw some more at you, you’re using FFOF and ff trio w/cal mag, have you done any flushes yet? Normally you’ll need to do one about the time you flip and possible once more towards the late middle of flowering. Plain water, 3x the volume of the pot, let it dry and resume feeding. You’re using synthetic nutes, so you may be getting a “salt” build/up.

Phytoplankton said:

Just to throw some more at you, you’re using FFOF and ff trio w/cal mag, have you done any flushes yet? Normally you’ll need to do one about the time you flip and possible once more towards the late middle of flowering. Plain water, 3x the volume of the pot, let it dry and resume feeding. You’re using synthetic nutes, so you may be getting a “salt” build/up.

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Thanks. I have done some flushes, and I’ve really tried to go light on the feeding. I do think low ph as diagnosed above is a likely culprit. My wife is hopefully grabbing me some ph up today to start to correct for the problem. The onset of symptoms was really fast after adding the nute enriched water, which further seems to support the idea of a ph imbalance. Buds are looking healthy enough, anyway. Learning…I really appreciate the insights.

I lightly feed once a week when I'm growing in FFOF.

I make sure to refresh the soil by up potting prior to switching to flower and go with it.

Some breeds are really heavy feeders and for those I add dry nutes to the top of the soil every 4 weeks.

I've noticed though that most of my plants do better when I simply forget the nutes all together.


I came to that realization with an outdoor grow. I had the same cut in the same size pot and same soil. Two outside and two inside. I thought I was really taking care of the inside girls with feeding, mean while the outside girls were getting drenched by the rain so much that I couldn't feed as they didn't need water. A few weeks of that and the inside girls were looking bad. Lockout, over fed, just sad. The outside girls were picture perfect (close enough) and then I learned.