Tips of leaves burning?

Help! I’ve noticed the leaves are starting to have burns on the tips of them. I’m only feeding them water 3-4 times a week and a compost brew every 11-14 days. No nutrients at all.
Any idea what’s causing this?

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I am a bit more concerned over the “tacoing” leaves than the tip burn. The tip burn certainly looks like “nute burn” but since you are not feeding, I am at a loss on that.

What is your temperature and relative humidity? Growing medium?

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Fox Farm soil
Humidity- high of 41 low of 33 its been hard keeping that humidity up where I live :frowning:
Temp high 29 C low of 20 C

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It’s seems to be just those top leaves also. Not the whole plant

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How close are your lights and what kind of lights?

Those numbers are not bad for Temp and rH as far as I know.

I set my temperature and rH setpoints based on the VPD (Vapor Pressure Deficit) chart.
I think that @blackthumbbetty may have a link to the chart, I only have a print out.

It is worth noting that with somewhat low rH and somewhat high temperature, the VPD is high which can cause excessive uptake of nutrients along with the water. This can cause nutrient burn, I think.

High VPD can also stress the plant in general but I am not certain of the details.

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The leaves are tacoing up, too. That means they’re not happy with the lights, heat, or humidity. If your temps and humidity are ok, you might want to raise your lights a bit.

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Flower VPD

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Thanks BlackThumb, I did not have it handy. I think that many growers could benefit from tighter control of temperature and rH to keep VPD in a healthy range. I have both of those charts printed out and I have used them to determine setpoints for different growth phases.

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Thank you!

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The light and distance certainly looks OK to me.

If you find where you are on the first VPD chart you may find that your plants are in the stressed (pink) region.

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VPD, along with pH, and proper light ppfd are the gatekeepers to healthy plants. They control how your plant eat, drinks, and breathes, as well as determining what, exactly, your plant is able to eat/drink/breathe.

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Exactly!

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