Light burn?

[Fantomlimb]

I posted this at the end of my nutrient burn thread but considering this is a different plant and different problem, I thought I’d start a new one. I started flower 2 weeks ago. When in veg, the plant was under a 105 true watt Vivosun light and a 30 true watt full spectrum bulb. When I switched to my flower tent, it went under a Mars Hydro 305 true watt TSW 2000. The plant is unfortunately really tall and I can’t figure a way to rig my light up higher as the air filter is in the way. I’ve already looped the 12” light hangs to get them to 6” hangs and the ratchet hangers cannot be shortened anymore either. However the Mars Hydro has a dimmer switch on it. Currently it is about 17” above the canopy and 80% power. So my questions are, does this look like light burn, and is there anything I can do short of taking the whole thing out of the tent? Should I lower the power? I only worry about not enough light getting to the lower parts of the plant, but then again I’ve removed a lot of that so there isn’t much down there anyways.

 

[013]

Yes thats the start of heat stress or light burn where the edges are folded up, it’s probably worse in the center of the plant. You could dial back wattage or maybe move filter to outside tent and raise fixture

 

[JohnnieJC3]

I wouldn't assume it's the light without checking with a Lux meter, I push my plants hard and have accidently left the light without raising in stretch and experienced minimal bleaching. Some of your leaves are pointed downwards, don't rule out feeding to much food. What style are you growing, soil or Coco or I see pebbles Hydro? PH fluctuations can cause all kinds of weird issues to come up.

 

[Emilya Green]

I don't see any light burn and at 17 inches away you are just at the suggested range of that light. If you check par charts they suggest flowering at 18 inches away.

What I do see is a deficiency starting up, not a burn. I suspect several things, but I too would like to hear more about your medium and what pH you adjust your fluids to before making any educated guesses as to what is causing your difficulty.

 

[SoGnotSOG321]

There's just never enough room in the tent, imagine if it was HID lights then no it isnt lights. You have a hungry plant I think, what its hungry for, is now the problem (Captain Obvious) to solve. I think some super cropping is in order or your problem with the lights will come later on for sure with your short space.

 

[Fantomlimb]

So some info on my set up. I’m doing DWC hydroponics with hydroton rocks. I have been a little lazy with topping up water everyday but I always get it by the next day and adjust PH when I do it. I try to keep PH between 5.5 and 6.5. Though I do catch it outside that range occasionally when topping up. Using General Hydroponics Flora Trio. Temps are around 72-74 degrees with about 47%-50% RH. This was a clone that was given to me. It was taken from a flowering mother so it’s already monster cropped. I took from the top to create more clones and topped it multiple times. Probably why it’s so bushy. I’ve never super cropped before and the thought of it makes me nervous. Also don’t have really any horizontal space left in the tent. It’s a 3’x3’x5’ tent and the plant is 3’x3’x1.2’ plus 1’ of bucket below it. Then 6” hanging wire and another 5” from the ratchet hangers. Even if I take out the filter, I don’t really have a way to shorten the wires or ratchet system. My only option is to take it all out of the tent, or use the dimmer to compensate.

 

[Fantomlimb]

Also i was using a Heavy Feed during veg at about 1.6-1.8 EC. I lowered it a bit for flower as I was told that was high when I had issues with my last crop. It’s now around 1.4-1.6 EC. Could it be it wants more food?

 

[013]

Understand on the filter & headroom problems. If you are cutting clones and doing monster-cropping then learning to supercrop is a natural extension of your skills as a gardener. I’m betting InTheShed has a tutorial, the main thing is go easy, try to avoid breaking the skin. A piece of tape will fix most limb breaks. Here ya go... InTheShed supercrop

 

[Fantomlimb]

Understand on the filter & headroom problems. If you are cutting clones and doing monster-cropping then learning to supercrop is a natural extension of your skills as a gardener. I’m betting InTheShed has a tutorial, the main thing is go easy, try to avoid breaking the skin. A piece of tape will fix most limb breaks. Here ya go... InTheShed supercrop

Is it ok to super crop this far into flowering? Also, about deficiency, i thought the brown spots also looked like a slight calcium deficiency but the yellowing of new leaves is throwing me off. That’s why I went for light burn since all the lower leaves are dark green.

 

[013]

Should be fine but break it up and do it in sections so as to avoid shock. Supercrop a few and wait, see how she responds the next day.

The browning could be start of deficiency... I was talking about the cupped up leaf edges in pic 3 being heat or light stress. Lower leaves are dark because plant has good N level for now.

that plant would do nice if it was strapped down better before flipping to flower, plus getting it wide and low would help with your height issues. You should try manifold or quadline next time and teach yourself how to train them. There’s a group quadline journal open to anyone plus they keep an eye on you which is really cool. I‘m soil grower & don’t know beans on hydro formats

 

[Fantomlimb]

Thanks for the help. My training method knowledge is all about topping and clearing veg growth. I think I’m pretty good at making wide and short, as this plant is 3x as wide as tall. I tried tying down the branches earlier but with having to get into the bucket to top off and mix new nutes, it got to be too much of a hassle to retie them back down. Biggest issue was that because this is a monster crop, it already acted like a cropped plant by splitting into like 10 different main stems pretty earlier along. My biggest thing with super cropping is if i lose this plant, I lose 7 weeks of veg time with no plant to back up and would have to start from scratch. Not easy with only bag seed lol. If I choose not to, could I make do with the dimmer? What would I be looking for to make sure i don’t have it turned down too low?

 

[NuttyProfessor]

your swinging your ph 100 times more alkaline and then 100 times more acidic 5.5 -6.5 , if your not topping up the ph will raise because the plant is using some food , then is too high locking out nutrients' the plant doesn't know if its coming or going lol you need to steer your plants more and concentrate on the right ph every time 5.6 5.8 early then up a tad ,6 maybe , ( if you want ) , focus in more , its doesn't work half hearted, trust me ive been there , you get what you put in

 

[Emilya Green]

So some info on my set up. I’m doing DWC hydroponics with hydroton rocks. I have been a little lazy with topping up water everyday but I always get it by the next day and adjust PH when I do it. I try to keep PH between 5.5 and 6.5. Though I do catch it outside that range occasionally when topping up. Using General Hydroponics Flora Trio. Temps are around 72-74 degrees with about 47%-50% RH. This was a clone that was given to me. It was taken from a flowering mother so it’s already monster cropped. I took from the top to create more clones and topped it multiple times. Probably why it’s so bushy. I’ve never super cropped before and the thought of it makes me nervous. Also don’t have really any horizontal space left in the tent. It’s a 3’x3’x5’ tent and the plant is 3’x3’x1.2’ plus 1’ of bucket below it. Then 6” hanging wire and another 5” from the ratchet hangers. Even if I take out the filter, I don’t really have a way to shorten the wires or ratchet system. My only option is to take it all out of the tent, or use the dimmer to compensate.

It sounds like you have things well in hand. You are going to need to do an experiment. It is my belief that because of the size of your plant, feeding at the rate you have been is not quite enough, hence the beginnings of a deficiency. Try upping your feed by 25% and see if this causes better color and a halt in the progression of the problem you are seeing. I think everything else you are doing is within normal ranges and should not be a problem. The alternate experiment is to assume that it IS a burn, and feed 25% less, hoping it will go away. It is my belief that this path will make the present problem worse.
It is your choice... you are the gardener in charge! Good luck!

 

[Fantomlimb]

your swinging your ph 100 times more alkaline and then 100 times more acidic 5.5 -6.5 , if your not topping up the ph will raise because the plant is using some food , then is too high locking out nutrients' the plant doesn't know if its coming or going lol you need to steer your plants more and concentrate on the right ph every time 5.6 5.8 early then up a tad ,6 maybe , ( if you want ) , focus in more , its doesn't work half hearted, trust me ive been there , you get what you put in

I should have been more clear, when I do a complete refill or top up I make sure it’s around 6.0. I was using the 5.5-6.5 as a range of where I try to keep it. As to it tasing when not adding water, sometimes it raises, sometimes it lowers. I’ve been using a chart that tells you what the plant needs based on water level, PH, and EC either raising or lowering. I’ll attach it. This is my second grow, I more or less did my last one the same way but I was adamant about topping Rez everyday and even lowering temp in Rez as it would get up to 76 degrees. This time around it doesn’t get that high as my light is right below the air filter wich removes about 5 degrees of heat from the tent and as such my water never gets above 71. Using hydro guard also. I was previously told that letting the PH wander a bit helps as different nutrients up take at different rates based on PH. Is this wrong think? I don’t have a light meter so I use Korona on my phone. It’s not perfect but gives you an idea. As it stands at 75% power and 16” the PAR value is 950 at canopy top. Just did a top up today and PH was 6.7. Lowered it to 5.9. I will try to keep topping up daily, however it’s hard some days to get to it before lights off as I have a 16 month old.

 

[Fantomlimb]

Here’s the chart I was talking about as well as one of my Creme de la Creme from my first grow.

 

[Fantomlimb]

As for super cropping, is this right?

 

[NuttyProfessor]

I think its Zinc , TBH , top of plant is showing not any where near the bottom where NP or K normally shows first , Zinc def normally caused by a high ph or a high stressed plant ( lights ) (heat ) etc also a high ph will stop the plant getting calcium , then its hard for the plant to take up (K), Calcium and potassium are as important as n & p, maybe more important , (k) keeps every thing mobile its the health element for the plant ,
I think i also just see the cal def coming through , just slightly, if you get the rust spots you will know better , top of plant
I would zoom in more on the feeding range ph , just to destress ,
Any ways that is my input
I hope you get her on track
I know how you feel, i have a crazy two year old girl lol , she is as mad as a brush keep you on your toes

 

[NuttyProfessor]

Here’s the chart I was talking about as well as one of my Creme de la Creme from my first grow.

This nug looks the dogs nuts !

 

[HydroponicFireman]

Plants grow taller because there isnt enough light and so they shoot up to get above the canopy of plants blocking their light. Theres no canopy of competing plants so I assume theres not enough light.

I dont know about you but I use like 1000 watts of light when growing...300 watts seems very low to me for plants that size.

Also, I would personally LST instead of topping

 

[Fantomlimb]

This nug looks the dogs nuts !

I’ve never heard that phrase but I’ll take it!