Yellowing, discolouration and minor spotting

[4d-Rock]

Hey Everyone, I have a plant in the tent that is looking a bit less than ideal and I’d like to see if I can limit the affect of whatever is happening and finish strong.

Here’s the info
Problem: Started as general light green colour of leaves, progressing to yellowing, with minor spots on some lower leaves. Just today some of the upper fan leaves on the Colas are getting a faint purplish colour (not referring to the obvious dark purple associated with the strain)
Medium/grow method; 2 gal fabric pots with Pro-mix HP peat
Feed and supplements used: hand watering til ~10% runoff, nutrients every feed. Using MegaCrop one part V2. Plain water first week, 2g/gal 2nd week, 3gal/gal 3rd week, been steady around 3-3.5g/gal since. I’ve been supplementing occasionally with 0.5g/gal Sweet Candy or Epsom, and 50ppm CalMag. One at a time. Also, added ~100ppm of Fox Farms Tiger bloom to last 2 feeds (I know it’s not recommended to mix lines, but MC seems K heavy for early flower and TB has higher P). Highest feeds have been total 625ppm incl. base TDS
Water source: Lake water, sediment/UV filtered, ~60ppm/7pH
Strain and age: Sweet Seeds Red Poison Auto, Day 40
Climate: 26C/50% daytime, 19-21C/50-60% night
Light used: Homemade COB fixtures, 4 total for a combined 210w. At top of my 5’ tent, now about 12-14” from top colas.
Additional info: The two Sweet Nurse CBDs on either side have been slower growing, but much greener overall. They all had some minor N clawing early on and backed off nutes for a few feeds. But the feed strength has been relatively consistent between the 3. Last week I checked the in pot pH with an Apera soil probe and the Sweet nurse came back at 5.8-6, the Red poison at 5.4-5.6. After which I’ve had my feeds ph’d to 6.1-6.3 to nudge it up.

Any help/suggestions would be appreciated!

 

[Blu_tri]

Just my opinion. There are others more experienced. Your plant is stressed. Figure out what you did to stress it. Change is the primary cause of stress. Keep growing brother.

 

[Arthur]

Need someone more familiar with MC than me, but that girl looks hungry to me.

 

[Proph]

Hey Everyone, I have a plant in the tent that is looking a bit less than ideal and I’d like to see if I can limit the affect of whatever is happening and finish strong.

Here’s the info
Problem: Started as general light green colour of leaves, progressing to yellowing, with minor spots on some lower leaves. Just today some of the upper fan leaves on the Colas are getting a faint purplish colour (not referring to the obvious dark purple associated with the strain)
Medium/grow method; 2 gal fabric pots with Pro-mix HP peat
Feed and supplements used: hand watering til ~10% runoff, nutrients every feed. Using MegaCrop one part V2. Plain water first week, 2g/gal 2nd week, 3gal/gal 3rd week, been steady around 3-3.5g/gal since. I’ve been supplementing occasionally with 0.5g/gal Sweet Candy or Epsom, and 50ppm CalMag. One at a time. Also, added ~100ppm of Fox Farms Tiger bloom to last 2 feeds (I know it’s not recommended to mix lines, but MC seems K heavy for early flower and TB has higher P). Highest feeds have been total 625ppm incl. base TDS
Water source: Lake water, sediment/UV filtered, ~60ppm/7pH
Strain and age: Sweet Seeds Red Poison Auto, Day 40
Climate: 26C/50% daytime, 19-21C/50-60% night
Light used: Homemade COB fixtures, 4 total for a combined 210w. At top of my 5’ tent, now about 12-14” from top colas.
Additional info: The two Sweet Nurse CBDs on either side have been slower growing, but much greener overall. They all had some minor N clawing early on and backed off nutes for a few feeds. But the feed strength has been relatively consistent between the 3. Last week I checked the in pot pH with an Apera soil probe and the Sweet nurse came back at 5.8-6, the Red poison at 5.4-5.6. After which I’ve had my feeds ph’d to 6.1-6.3 to nudge it up.

Any help/suggestions would be appreciated!

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What is the ppm of your run off?

 

[4d-Rock]

Just my opinion. There are others more experienced. Your plant is stressed. Figure out what you did to stress it. Change is the primary cause of stress. Keep growing brother.

Thanks. Haven’t really changed much lately. Other than the increase in pH feed from 6 - 6.3

Need someone more familiar with MC than me, but that girl looks hungry to me.

I wondered about that as well. Though MC is weird in that I’ve seen others on the board do great with high feeds and some with pretty low strength. But I’m always tentative because it seems more often the problem is too much.

What is the ppm of your run off?

Haven’t checked recently, but a couple weeks ago I saw that it was in the 1000+ range so I increased my water volume per feed because I don’t think I was getting enough runoff. After a bit it went back to 100-200 above input. I’ll be feeding tomorrow evening so I’ll check again.

 

[Mañ'O'Green]

Part of this looks genetic to me but I also think you are over-feeding and perhaps out of balance with the additives? I would drop back to 50% of the MC only for a while and increase the run-off to 20% for the next couple of fertigations. The peat hangs on to nutes a little tighter than coco. I would add Kelp, Fulvic Acid and B-vitamins to the next fertigation if you have them on hand.

 

[Blu_tri]

I like to keep mine no more than 50 over input. Mine never liked sweet candy. The 100 ppm addition of tb may have stressed it while it didn’t bother the other plant. Just how it is.

 

[Proph]

Thanks. Haven’t really changed much lately. Other than the increase in pH feed from 6 - 6.3


I wondered about that as well. Though MC is weird in that I’ve seen others on the board do great with high feeds and some with pretty low strength. But I’m always tentative because it seems more often the problem is too much.


Haven’t checked recently, but a couple weeks ago I saw that it was in the 1000+ range so I increased my water volume per feed because I don’t think I was getting enough runoff. After a bit it went back to 100-200 above input. I’ll be feeding tomorrow evening so I’ll check again.

I've never an auto over 500ppms.. And that was for the last 2 weeks of flower.. The leaves are cannibalizing.. Meaning the plant is feeding on the nutrients stored in the leaves, instead of the nutrients in the pot. That could be due to lock out, build up, ph, etc.. But something is stopping the plant from accessing/using the nutrients that you are feeding it.

 

[4d-Rock]

Part of this looks genetic to me but I also think you are over-feeding and perhaps out of balance with the additives? I would drop back to 50% of the MC only for a while and increase the run-off to 20% for the next couple of fertigations. The peat hangs on to nutes a little tighter than coco. I would add Kelp, Fulvic Acid and B-vitamins to the next fertigation if you have them on hand.

Ya, i thought there was a genetic component there too, but likely something else. My balance of nutrients could be off and I'll try what you suggested of backing off a bit and increasing runoff (currently I'm mixing 3L of feed per 2gal pot, usually gives me 10-20% runoff). I only have the SeaKelp from Greenleaf Nutrients, but no Fulvic or B-vitamins. Also, the Sweet Candy I have is the old version before they started adding some of the Fulvic/Humic acids and kelp.

I like to keep mine no more than 50 over input. Mine never liked sweet candy. The 100 ppm addition of tb may have stressed it while it didn’t bother the other plant. Just how it is.

Runoff at 50ppm over input? That seems crazy to me, I don't think I've ever had a runoff that is that close to input. I suppose it could mean that I'm consistently over feeding, or need to use plain water between feeds (which I thought was what you are supposed to do in peat mediums). Maybe my collection method is flawed, or the salt buildup on the outside of the fabric is tainting the results?

I've never an auto over 500ppms.. And that was for the last 2 weeks of flower.. The leaves are cannibalizing.. Meaning the plant is feeding on the nutrients stored in the leaves, instead of the nutrients in the pot. That could be due to lock out, build up, ph, etc.. But something is stopping the plant from accessing/using the nutrients that you are feeding it.

Hmm, It's very possible that there's a lockout then. I'll check the in pot pH again this evening and report back with that and the runoff ppms with a reduced strength feed.

Thanks everyone for the input!

 

[Proph]

Pro mix doesn't have nutrients in it.. Your run off ppm should be the same as the ppm of your feeds, if not lower.. Runoff ppms are one of the only ways you can tell if, and/or how much, your plants are feeding.