Hello! I am looking for some help with my DWC grow. I am using a rubbermaid container growing with DWC the strain of Cole Train by DNA Seeds (indica dominant). I am almost 3 weeks in to flowering I am using the full Lucas Formula (using the 100% nute top off everyday method) and am running at ~900-950ppm at a .5 conversion and I am using RO water pH stays from 5.75 to 5.95 on average also i really dont think it is a pest/bug problem as I have not sensed any bugs at all if anyone needs any more info from me please ask - - - - - Its mostly the upper leaves that are affected, although the lower and older leaves are also effected but not as much as the top leaves (meaning lower leaves are healthier), they are getting these small brown spots, and all over yellowing, crispy edges and the tips are curling up and down. the fan leaves are most affected, and the bud leaves are also affected but less. (the "sickness"/"problem" is most potent on the fan leaves, but is also affecting the bud leaves and such) I do not think it is a heat stress issue, my air cooled 1000 watt is over a foot away from the canopy and does not burn my hand. I honestly am not thinking it is really a deficiency either but I am a near total noob with hydroponics, I come from soil this is my first grow. Appreciate any and all assistance, It is mainly the top of the plant and the new growth thats affected, but some of the bottom growth is affected the same way too but to a less potent effect. GOT A PICTURE OF A LEAF !! Here ya go blades, please help ! Keep in mind this was taken from an upward pointing down angle, pointed towards the canopy of my plants. Appreciate it as always! As you can see in the pic, the leaf has brown spots and yellowing and everything can be seen I believe
If noone knows whats wrong or close to whats wrong I will just flush out my reservoir in a couple days and add fresh lucas formula solution and see if that helps.
This def looks like it's from the light. Now, how many plants are you using? That is a STRONG ass light. Can you dim it?
I am using 5 plants and they take up nearly the whole ~3.5x3.5x6.5ft tent. They are kind of overgrown. A little over a foot is the max distance I can move the light from the canopy. Now that it is starting to warm up a lot outside, my home A/C will be blowing more cold air for the tent to use, so thats a plus. So this looks most definintely like a heat stress issue? Any other guesses besides that? I have no way to dim my light i dont think it is dimmable. The canopy of the plants does get fairly warm, its not burning my hand warm but it can get slightly uncomfortable when the A/C hasnt ran in awhile. (my A/C vent is on the ceiling of the grow room with the tent in it) Thank you for the input zoomme. Do the leaves look specifically heat stressed and nothin else? Its mostly the fan leaves with the problems, but some of the bud leaves have minor problems (same ones as the fan leaves but just less damaged so far)
You can install a cooling tube. I can't see what else it can be. You could also bend the sites over and get them a lil further away. Lst but not completely bent over. Like curved.
I do have a cool tube with a 6 inch fan blowing through it, the canopy of the plants is like 12-14 inches away, it feels warm but its not burning my hand or anything, my arm will usually get too tired before my hand will feel too hot. I can try to do some more bending but ive already done some training on them, they just stretched so fast became too tall. - - - - - I was kind of thinking it could be a nutrient problem or something, I dont dump my res every week like some, I do it the other way, topping it off with 100% nutes every day. Do you adjust your pH at all with down/up products zoomme? I noticed you do lucas formula as well. Every 3-4 days I will put like 2 entire plastic pipette worth of pH down to bring it back to ~5.8 from ~6.0
Okay I managed to be able to raise my lights up more with some string & knots... It is now ~16-18 inches away from the canopy
That's good. I do adjust but I let my ph swing. I don't adjust often though. By that I mean, maybe MAYBE every week. Different nutrients are taken up at different ph's. So I will let it go between 5.2-6.2 They Lucas formula is very reliable and unless you did it wrong, I doubt it would be the nutes or ph. Try the lights. Unless it progresses... In which case, empty res. Fill back up with half strength nutes then grad increase. Don't do a full flush during flower. Do one thing at a time. Don't over fix (don't make more then one change at a time until you see the effects or the problem gets worse) or you will never figure out what the problem was and you'll be doomed to repeat it lol. Also, the burn that is present won't go away. It's there to stay. The damage will hopefully stop now. Good luck!
I'm also using Lucas formula and a hybrid dwc system. I'm also using a 6 in cool tube, tho with a 400 watt bulb. OTHO my light is WAY closer and i've only burned a few leaves cos they were touching the tube, but they didn't quite look like that, and my lower leaves were unaffected. If moving the light further doesn't seem to help then i would think its either nute burn or maybe a lockout. Since your doing the addback DAILY to maintain the 100% strength, IMO there's a higher chance for certain elements in the nutes to buildup and cause lockout and/or possible certain toxicities to develop. My recommendation is to let the res go for at least a couple of days to allow the more of the different Elements to be used and PPMs to drop and ph to raise to about 6.0-6.2 When you do your addback it will bring the Ph back down to to the ideal 5.5-5.9 range. my reasoning behind this is that each Element has a different availability/lockout Ph range and by letting your water's Ph to naturally move up and down your plant has the chance to access all available nutes in the res.
LOL i just said the same thing. didnt see your reply until i posted and the page refreshed good to see im on the right school of thought as im still learning myself
1. are you adding calmag back to your RO'd water? if not this can be very problematic on several levels 2. what exactly are the temps at canopy level??? ive slammed a cooled 1k inches from canopy with zero issues 3.not saying this looks exactly like it but have you considered the tent your using??? offgassing is real and sux massive ass without more info id still just be guessing so good luck and i hope you sort it
sensikid- 1. no im only adding floramicro and florabloom as per the lucas formula 2. they are no hotter than 80 degrees at the very top of the canopy, between 73-80 depending if the air conditioners blowing cold air or not 3. I have used this same tent for ~10 soil mix grows, so I wouldnt think it'd still be offgassing if that was a problem zoomme- It is hard to tell ill have to give it some more days, it does make a lot of sense for the problem to be heat stress, because why else would it just start with the newest leaves at the top. appreciate the input everyone, its been 35 days of 12/12 lighting, and ~22-24days of flowering would it be wrong to cut off some of these dying (heat stress is the best guess) fan leaves? i dont want to stress them out too much and cause a hermie, but I could get a lot more penetration if these nasty leaves were out of the way.
1. when you RO your water you remove some things you dont want and some things YOU ACTUALLY NEED...bicarbonates(your calmag) help your water and nutes ph level and adjust...my advice is to atleast try ppm'ing your water to 100 with calmag after the RO..if you are having probs with nute def/lockout this could solve it 2.heat stress??? really??? 73-80??? dont think so mang...unless you have zero moving air on your girls,i highly doubt its the heat now on a side note...you might wanna try not topping off for a few days and monitor your ppms and ph....see if your plant really is digging your feed schedule...you might be to hot or even too cold,tho i doubt it good luck sir chasing your tail sux
o and i wouldnt cut anything off till 1.its completely crisped or 2. you identify your problem.... if its a def or lockout the plant is gonna NEED to feed on itself till you can sort it out
I grow a blue widow that pulls that same bullshit. Perfect plant until week 3-4, then (without cal/mag+) the spots appear and get a whole lot uglier as it progresses. Just a thought. (you can foliar feed with a weak mag solution for fast results, or to just to see if that's the problem, they green up fast)
First, I am only on my 4th grow (all DWC), so keep that in mind. However, in looking here at a site I have found useful (Marijuana Plant Abuse) your leaves look exactly like nute burn (figure 4 reference). I know nothing about Lucas formulas, but with Technoflora (what I use) it is my understanding that once you set the brew you cannot add to it effectively without throwing things off. Their Boost product must be added first, and cannot be added to an existing brew. Sounds like Lucas is different, but something ain't right! I would flush them a couple days in RO water, then do a "light" brew that's getting them to around 900-1000ppm and keep your ph between 5.8 and 6.1. I tend to go lighter on nute strengths and am still learning what levels seem best and how to read my plants, but I've always read it is better to go too light than too heavy. Good luck, hope that doesn't confuse the issue even more!
negatory good buddy...nute burn DOES NOT begin with "the little brown spots"...if your feed is too hot ,your leaf tips will burn up and the crispy goodness will progress inward...and since the OP mentioned he is having NO drastic ph swings(espescially down),im quite sure its a def/lockout...