This is the second week into flowering, I am using DWC with bubblers and an HPS light, and for the past two or three days the fan leaves near the middle and top are really cupping in and curling down as well. I have the lights at 12/12 about 20" above the top and the res temp is right around 70 degrees. For the past two days the PPM has gone up from 870 to 904 to 927 tonight? The Ph however is rising overnight so im not sure what my problem is. The top leaves that are cupping feel somewhat dry and crispy while the lower leaves feel soft. Im using canna flores nutes whith cannazyme and a little bit of boost. Could it be a magnesium deficiency? Any help would be greatly appreciated
I'm no expert, believe me, but I can suggest a resource: Weed Farmer's Marijuana Seeds, Cannabis Growing: Cannabis Grow guides! and look up cannabis nutrient disorders. See if anything makes sense. I had the same kind of ppm and ph changes like you describe in the past and all I could do was to keep adjusting the ph and ppm to where I wanted it and felt safe. My plants seemed to be particularly sensitive to higher nute levels... anything over 850 and they got upset. I guess it can be very strain dependant on what levels work best. What is your tank ph like? I do understand that at certain ph levels the plants cannot absorb certain nutes, and the window where they can get most everthing seems to be rather narrow, especially when your levels are fluctuating. I got a chart from someone on this forum last time I was having problems that helped. All I can refer you to is http://forum.sensiseeds.com/uploads/19197/nutrient chart.gif Hope that helps.
Pics would help.... But usually means they're using more water than nutes... So most likely the pH is causing lock out... I would lower the pH to 5.6 and see if that slows the ppm climb.. If it does, I would drop the ppm to 800, and run 5.6 pH..
Crispy leaves are usually a sig of salt burn. Do a 24 hour plain water flush. The cupped leaves could be heat, humidity, or ph problems.
I checked on the girl tonight and the cupping leaves looked slightly better, the ppm jumped up again to 925...so I added half gallon of ph'd water and lower the ppm back down to 780 and set the ph to 5.5 and raised the light slightly...so hopefully these changes will help. And im not sure how to post pics....
If your ppm is going up, your giving them to much nutrient, it is best if the ppm stays level or goes down. The best ph for hydro is 5.8 with a range of 5.5 to 6.2.
It's environmental stress... Heat, Humidity, or wind stress... But from the looks of it, I'm going to say they are heat stressed... Is the lamp to close??? What is the chamber temp??
Green 247, Hey man, stumbled across your thread and saw you had cupped leaves issue. http://forum.grasscity.com/attachme...st-hydro-grow-dwc-1.11.11-day-39-top-view.jpg http://forum.grasscity.com/attachme...ydro-grow-dwc-1.11.11-bud-shot-nrng-sgh-2.jpg I had the same issue on my first hydroponic trial as pictured above. How cold is it getting? My recorded showed my temps being below optimal (58-72), perhaps environmental stress? Too hot or cold? If not that, i've increased my air ration significantly after the first grow and have never had a repeat of the issue. Although, i haven't had grown during the middle of winter since then. I'm leaning more towards environmental stress though. Good news is it didn't really impact my plants and they "powered through" it after a little while. Gotta love the resilience of weeds. Another theory is that your mentioned your ppm increasing, which would suggest that the plants were over fertilized. In this situation, the plants attempts to expel mobile nutrients via the roots to the grow medium. This in turns causes the plants to loose some of it's "stiffness" because it has to fight against the concentration gradient of osmosis (wanting to expel excess nutrients in the plant to a higher concentration in the nutrient solution) limiting itself from the up take of the nutrient water solution. I"m kinda high and rambling, but i wasn't too dialed in back then on my nutes and it could have been nutrient stress. Plus your plants look really green, hard to tell though in hps lighting. You could try to stabilize your PPM and let the plants grow until they lighten up slightly before increasing the nutes again. Hope all this helps, Good Luck!
thats some heavy duty nute lockout. I see ur using cannazyme which I was going to rec lower your ppm. theres a leaf in ur pic on the left side in the middle the tip is turned not straight the strain I'm running thats the first sign of overfeeding when I see the leafs start to turn or twist I know to lower ppm. do you have rhino skin or any other supp with silcone in it. cause that will help fix the prob.