Greetings All, The past couple of days I've noticed some of the leaves on my plants have began turning brown on the edges. They appear burned, and I'm guessing it's either too many nutrients, too low a ph, or (most likely) maybe my 1000 watt hps light is too close (has anyone seen this before)…? Although these “bad leaves†represent a very small percentage of the total (so far…??), as a complete newbie (and being so close to the “finish lineâ€), I am getting a little concerned. This is currently week number 7 for the 6 plants in my bloom-room. 6 plants (hydroponic) under 1000 watt hps Using “Botanicare†nutrients (following label instructions) Currently showing PH of 6.0 in reservoir Bluelab truncheon shows 1.6 to 2.0 (1120 to 1400 @ EC x 700) in reservoir Daytime temperature in room (at remote thermometer) = 79 ~ 80 Fahrenheit Closest leaves to hood min. 15†Closest flowers to hood 8†(flowers showing no signs of burning)…? No indication of pest infestation Even tho I can easily hold my hand above the tallest cola for 30 seconds, I suspect the light may be the cause. Has anyone seen these symptoms before? Should I ignore it, or could it become more serious? TIA for any and all advice! ToddL
unless your hood is air cooled you need to move that 1k further away... 8'' is way too close. this is a 1k, not a 400 here... i have a hard time believing you can keep temps under 80 with your 1k hps 8'' away from your top bud.... you need to measure the tempature at the TOP of your canopy... not ground level or just overall ambient room temp.... can you get a theromometer with a sensor on it? i picked up one for like 10 bucks at either walmart, or home depot.... and it was like a 2-3 ft cord attached to the thermostat with a sensor at the end of the cord... so i can just plop the sensor on top of a few leaves at the top of my canopy and get an accurate reading.... your thermostat may say 78-80 degrees, but the temp 8'' away from your bulb is what you need to measure... temp can vary more than ud think inside a room at different heights. 24'' is the rule of thumb, but quite often people can get closer than that.... for instance mine is probaly like 12-16'' away from the top cola... a lil better than 24.... but ive got a great ventilation system going and 4 box fans inside my room.... 8'' just seems a lil close.
It is air-cooled. I do have a remote thermometer as shown (and labeled) in the "bloomRoom1" image on my initial post. Having said that, I will raise the light. However, my real question is have you (or anyone else) seen leaf damage similar to what I have. After speaking with a family member about this, it was suggested the damage could be a result of water burn (ie: too much water). Each plant is in a double bucket (one bucket sits inside the other). The top bucket has the plant (in rockwool cube), and had a lot of 1/4" drainage holes drilled in the bottom. It is filled with clay-balls (lava-rock). The bottom bucket acts as a reservoir. Nutrients are pumped (by air) up from the bottom bucket, then dispersed via a 6" circular tube (with drip-holes) onto the lava rock, where it then drains back thru into the bottom bucket. I lifted one of the top buckets and discovered that a huge ball of white roots had grown thru one of the drainage holes (in the bottom of the top bucket), and was floating in the 3" ~ 4" deep nutrient pool. Also, I have been running the air pump (that circulates the nutrients) during the 12 hour light cycle, then shutting it off at night. Therefore, assuming the leaf damage is a result of the roots floating in un-circulated water overnight (and not getting enough oxygen), I am considering leaving the circulation pump on 24/7. Next time around, I may outfit each reservoir with a "rock bubbler" to better keep the nutrients oxygenated. Finally, I still wonder if anyone out there has examples of leaves burned from being too close to a light? I'd like to compare their appearance to mine. Thanx! ToddL PS Sorry to have rambled on so long...
I have got a few leaves that were burned by my light and they look completely different. It's not a uniformed pattern like what yours have. I don't think I have any pictures of it, but you can deffinitely tell the difference. The bubblers always on in the res is a good idea, especially if the roots are in the water! Take note that because your plants aren't getting much nitrogen since you may have switched to flowering nutes, the plants will start to suck what remains of it out of the leaves to help sustain itself a couple of weeks before harvest if you are flushing them with just ph'ed water only. Which you should be doing if you are so close to harvest. Looks like nute burn though! GOOD LUCK!!! and HAPPY SMOKING!!
Appreciate the input. Now that I think of it, what you're saying makes sense. The burn pattern would not be uniform if it had been caused by light. Last time I changed nutrients, they were a little high on PPM, so two days later (which was yesterday) I thinned the mix by adding ph balanced water. Hope that's it!
Those affected leaves might not recover, just watch the plants and make sure it doesn't spread. Sounds like you already found the problem.
That definitely looks like some type of nute deficiency. Necrosis on the tips of leaves is almost a sure sign of that. I can't think of any other prob that shows just that symptom. That said, you say your in week 7 but still giving nutes instead of just water? Not too many strains get nutes after the 7th week. They should start showing signs of deficiencies cause you arent adding nutes anymore. I wouldnt even worry about the plants at this point. Not much you can do wrong at this point, cept set fire to them, lol. Just keep em watered and cut all nutes out. They look good to me, enjoy...
After much reading on this problem, I see something I'd somehow overlooked. Periodic flushing is required. I thought that flushing was done only just before harvest, but now see that I should have been flushing at least every two nutrient changes to avoid toxic salt build-ups and/or lockout. Just purchased a bottle of Botanicare "Clearex", and per instructions, will flush the girls tomorrow AM. Thanx to All for your help! ToddL
thats a P defiance, the dark green leaf, redish tents on the leaf margens, and necrosis says that... ur flowering, its common... ur graden looks really pretty, its not bad at all. i would up the feeding a little and see what happends good luck
I've been growing hydroponically for the past 3 years and didn't know about periodic flushing either. From what I have learned in just the last 2 days about the Lucas formula (I should have read about Lucas formula years ago) I should double the size of my next harvest.
I would say your problems were twofold. Leave the airpumps on and flush weekly. For an 8 bucket system (waterfarm) we use about 55 total gallons of water, 20 for the clearex flush, 20 for a fresh water flush following that then the refill with nutes.
might be a mag deficiency. the spots look sort of like rust spots to me and i was told that might be a sign of a mag lockout prob from salt build up. those plants look gorgeous though i don't think a few leaves is anything to worry about. happy budding