Am I underfeeding this plant?

[Daramus]

Hello. This is my first post on this forum. I am a new grower and this is my 4th grow. I am concerned that I may be underfeeding one of my plants. Today is week 6 day 1 of flower. About a week ago, overnight, my plant developed tip and edge burn across the entire plant. Also, I have been losing about 3 - 6 leaves a day from the bottom of the plant as they are yellowing and getting brown from the tip inward.

Strain: Aurora Indica
Soil: Fox Farms Ocean Forest
PH: Runoff has been dark to light yellow (I use chemical test) indicating in the 6 - 6.9 range
Nutes: Dyna-Grow Bloom and Botanicare Sweet Grape
Temp: 65 - 78 degrees night / day
RH: 35% - 45%
Water: Mixture of RO and tap to about 150 base PPM then add nutes from there.
Feeding PPM: I feed about 600ppm every other day and have barely been able to keep runoff PPM just over 1k. If I feed every other time PPM will drop to 600 or below

The plant I am worried about is admittedly too large for the container it is in. I grow in a 2x4 and it takes up most of the tent. It requires water ever other day as opposed to the neighboring plant that gets watered every 4 -5 days. Also the fabric container seems to have lots of buildup and discoloration. I assumed this was because of the small fan blowing nearby that may have accelerated water loss via evaporation and left salts in the fabric. The other plant does not have the same issue.

In fact, the other plant (same strain) has darker green leaves, no leaf burn, and has not lost one leaf. The runoff on the smaller plant was as high as 3k and is now just above 2k. It has none of the problems of the bigger plant and it has a lot more nutes available during the entire grow. This is why I suspect the larger plant would benefit from more nutes.

Is the leaf burn a lack of phosphorus? Any advice would be appreciated. Thanks.

 

[hotrodharley]

Hello. This is my first post on this forum. I am a new grower and this is my 4th grow. I am concerned that I may be underfeeding one of my plants. Today is week 6 day 1 of flower. About a week ago, overnight, my plant developed tip and edge burn across the entire plant. Also, I have been losing about 3 - 6 leaves a day from the bottom of the plant as they are yellowing and getting brown from the tip inward.

Strain: Aurora Indica
Soil: Fox Farms Ocean Forest
PH: Runoff has been dark to light yellow (I use chemical test) indicating in the 6 - 6.9 range
Nutes: Dyna-Grow Bloom and Botanicare Sweet Grape
Temp: 65 - 78 degrees night / day
RH: 35% - 45%
Water: Mixture of RO and tap to about 150 base PPM then add nutes from there.
Feeding PPM: I feed about 600ppm every other day and have barely been able to keep runoff PPM just over 1k. If I feed every other time PPM will drop to 600 or below

The plant I am worried about is admittedly too large for the container it is in. I grow in a 2x4 and it takes up most of the tent. It requires water ever other day as opposed to the neighboring plant that gets watered every 4 -5 days. Also the fabric container seems to have lots of buildup and discoloration. I assumed this was because of the small fan blowing nearby that may have accelerated water loss via evaporation and left salts in the fabric. The other plant does not have the same issue.

In fact, the other plant (same strain) has darker green leaves, no leaf burn, and has not lost one leaf. The runoff on the smaller plant was as high as 3k and is now just above 2k. It has none of the problems of the bigger plant and it has a lot more nutes available during the entire grow. This is why I suspect the larger plant would benefit from more nutes.

Is the leaf burn a lack of phosphorus? Any advice would be appreciated. Thanks.

More likely a potassium deficiency. Why are you wasting time measuring runoff pH? And your runoff ppm is crazy. You’re overfeeding obviously. Are you feeding every time they’re dry enough to take liquids?

 

[Daramus]

More likely a potassium deficiency. Why are you wasting time measuring runoff pH? And your runoff ppm is crazy. You’re overfeeding obviously. Are you feeding every time they’re dry enough to take liquids?

The runoff PPM of 2k - 3k was not anything I put in as it was from the pre-charged FFOF soil. I have seen 4k runoff from FFOF right out of the bag. 600 - 1k runoff is crazy levels for a plant that size? The smaller plant I have never fed because the runoff was always high and there were no symptoms to indicate a lack of nutes. The larger plant I was feeding every other time when the symptoms in the pictures appeared. I started feeding at the levels described in the initial post only when problems came up in order to correct the deficiency. Not sure that was the right things to do, hence my post here.

Thanks for the potassium recommendation. How do you suggest I remedy my potassium problem?

 

[hotrodharley]

The runoff PPM of 2k - 3k was not anything I put in as it was from the pre-charged FFOF soil. I have seen 4k runoff from FFOF right out of the bag. 600 - 1k runoff is crazy levels for a plant that size? The smaller plant I have never fed because the runoff was always high and there were no symptoms to indicate a lack of nutes. The larger plant I was feeding every other time when the symptoms in the pictures appeared. I started feeding at the levels described in the initial post only when problems came up in order to correct the deficiency. Not sure that was the right things to do, hence my post here.

Thanks for the potassium recommendation. How do you suggest I remedy my potassium problem?

Yes that’s crazy runoff at this point in the grow. Indicates overfeeding as plants obviously unable to use them. But of all the elements potassium is the most adaptable to pH so I’m wondering why you have what appears to be potassium deficiency. I might be way off base.