Heat/Light/Underwatering?

Hey guy, it's my first day here, and i was hoping you could help me figure out this problem I'm having. The strain is an untested strain called Velvet Ice, a cross between Ice and Velvet Kush. The leaves started yellowing a few weeks ago, and i was assuming it was a low-nitrogen problem, but now i know i was wrong. As you can see the leaves are drying up and dying, and I can't figure out why. This plant is under a 400 watt HPS, which is right next to a 600 watt HPS(about 32" center to center), and is about 20" above the plant in an open reflector. The other plants around it also have yellowing, but are not as effected as this strain. I also did the 'hand test' and it isn't that warm. My plants in veg are about 4" closer to a 400 watt HPS, and look fine. They are on 4/5 gallon pots, in soil, and get watered every other day, and I never let them get too dry(I don't think). When i go to water, I check the soil with my finger, and it's still a little moist, a couple inches down, so i don't think it's from lack of moisture. Also, I keep a fan on them at all times, sweeping across the tops of the plants. The soil PH is 7.0-7.1, and i use DynaGro Bloom fert, as directed. Anybody have any ideas, or have seen this before?

Also, they are about 5 1/2 weeks into bloom right now. The temp hovers at around 82* and the humidity stays around 45%.

Here's some bigger pics...

Also, if you notice, there are some leaves down lower on the plant that are effected, and other leaves closer to the top, that look fine. I have several other plants effected by this, and one is a strain called Velvet Kush. I have a Crystal plant that is directly under the 600 watt HPS, getting hammered with light, and it looks healthy as hell. If it was heat stress alone, you would expect the leaves to burn in an area where the heat is at the highest concentration. These leaves are all near the tops, but the damage pattern is random, with one or two leaves among a handful being effected. I have moved the plants around, but not in the last 2 weeks.

Anyway, I know it's not something as simple as just backing the lights off. I think it's a combination of a couple things, so I'm hoping to get some ideas, and go from there.

I used the same 400 watt light during my last grow(different strains), and had it at least 5" closer, with only a minimal amount of yellowing/stress. Also, it was 5* hotter too.

Could it be ventilation? As in, lack of fresh air?(not temperature) Contributing? I use the air from the downstairs of my house for fresh air right now, because I haven't been able to upgrade to carbon filters and a good ventilation system yet. It's coming soon.

Hi i have recently started my first grow so im not suggesting that this is the cause of your problem but you definitely need to lower the p.h level of your soil it should be between 5.8 and 6.5, i had similar problem though not as severe but once i got p.h level right i noticed vast difference! Hope it helps!!!

Hey Jawbrodt, glad to have you with us. Now let's get to the plants. Which by the way, sounds like a pretty interesting breed. I think you could have a magnesium deficiency. Get some CalMag and use as directed Also, the newb is right. Since you're in soil, your pH should be around 6.2ish - 6.5ish. Doesn't need to be perfect. But the pH at 7+ is way too alkaline. I would start with those being your main issue. You also look like you're burning the plants. You are using 2 different lights but together they are at the equivalent of 1000W. A 1000W lamp should be low enough that when you put your hand on the top cola, it doesn't burn your hand, but it should be high enough that your light is able to be dispersed over the canopy. Most grower's are usually right between 18" and 31" with a 1000W setup. Your temps are a little high as well. Ideally you should be around 75* - 78* F.

check ur ph and give them a flush, maybe check to see if there root bound.

Thanks guys, I was suspecting that PH was part of the problem, if not the whole problem. Also, I forgot to add something in my OP. I sprinkled some pelletized lime over the top of the soil at the beginning of bloom, which was a mistake. Although I used a long wire probe to worked some of it deep within the soil, I'm sure i created some 'PH hotspots', as well as making the upper soil PH higher than at the bottom, probably significantly so. So, if they do have a cal/mag deficiency, I would guess that it's because of overuse, locking itself out. Plus, the wacky PH distribution contributed, I'm sure. That "wacky PH distribution" would also explain the 'randomness' of the damaged leaves. Also, I have two different sized pots in this run, and the smaller ones are the ones that are effected worst, which would also back up the over-lime theory. The larger pots did a better job at neutralizing the lime that i put in, through larger soil volume.

Hmm.....Well, I guess there's 3 things I need to do. First, I'm going to remove the very uppermost layer of soil(without damaging the roots) and replace it with 1-2" of fresh stuff, and that should get rid of alot of the lime. Then I plan to flush them, which they could use, anyway. Finally, I'll start feeding them with a PH adjusted mix, probably somewhere around 6.2, maybe even a little lower for the next 2-3 times.

Yeah, I agree that the light isn't the problem. The light is bringing out the problem, but is not the problem, itself. I ran that same 400HPS in 92* heat, and had it as close as 12" without any problems. So it's logical to say that it isn't the problem, because it's only 80-82*,(a little warm, but not excessive) and averaging 20" from the canopy.

Well, it's time to do some flushing, eh? Damn.LOL

Thanks for the advice

My babies had symptoms like yours, but in my instance, it was overwatering. 'Not saying that is your concern, but I am learning that it is better to underwater a little bit instead of overwatering. There looks to be some light/heat issues too. I'm not an indoor guru, so I hope I don't mislead you. I grew outdoors for over 30 years, and the biggest issue I have with my new indoor attempt, is that I overwater. To me, it seems as though indoor plants don't need as much water as much as the outdoor crops.

...Just my .02.....good luck my friend

as to over watering, you say water every other day, that seems like a lot to me since mine go 5 days between watering

but to me your problem sure looks like heat stress/burning

be curious to see if it really is a PH problem?

riddleme said:

as to over watering, you say water every other day, that seems like a lot to me since mine go 5 days between watering

but to me your problem sure looks like heat stress/burning

be curious to see if it really is a PH problem?

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I would have to disagree to a degree here. I think that the lights may have caused a slight problem, but I don't think they were the initial problem. I think that due to the plant having a deficiency and too much of a pH fluctuation, it could have weakened the plant therefore causing some issues with the light and temperature. Just MHO

rreign said:

I would have to disagree to a degree here. I think that the lights may have caused a slight problem, but I don't think they were the initial problem. I think that due to the plant having a deficiency and too much of a pH fluctuation, it could have weakened the plant therefore causing some issues with the light and temperature. Just MHO

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I just flushed it down to 110 PPM + 35 PPM for the water I use, at 6.7-6.8 PH.

The runoff PPM was about 800 to begin with, so I definitely cleaned it out. I also replaced the top layer of soil with fresh stuff, plus added an extra inch. I did that because i had sprinkled pelletized lime on top, a few weeks ago,(mistake, I know.lol) and wanted to get rid of as much as possible. Probably won't be a 'miracle cure' but it should help.

UPDATE: I flushed them all down to 100 PPM, then fed them and gave 'em a little root enzyme. I found out where I fucked up, and i'm embarrassed to say it, but I will. I switched to new fert about 3-4 weeks ago, and never checked the PH. I've been waiting to buy a better meter, so I skipped it, figuring that the fert would be the same as the last stuff.(lazy mistake, I know. WTF?) When I mixed it up and checked it, it was 5.2. Holy shit, no wonder why they're suck!

The runoff started out at 5.8 when i started flushing, with 6.8 water going in. So yeah, the soil was quite acidic. When i got done flushing, the PH was up to 6.8, so now everything should be good to go. 3 1/2 - 4 weeks left to go with bloom, so they should recover nicely, and still give a good yield. Sweet.

I'll update when I see some results.