I have a little over four week old girls that have had trouble keeping thier leafs because the older leaves keep turning yellow with brown tips followed by leaf wilt and death. The new leaves always look great. I had them under T-5's for 3 weeks and under a 400W MH for a week. The temp was at 75 with the T-5's and 80-82 F with the MH about 40 inches away. I was advised it was heat stress and moved them back under the T-5's and was wondering if thier are any other possible problems. There is good ventilation the PH is about 6, no ferts yet and I water them about every 5-7 days. I first started watering them every 2-3 days. So could this be a sign of initial overwatering? They have been on the 5-7 watering for 2 weeks with no signs of improvement. Any ideas I really hope too save these guys. Thanks everyone for your advise.
4Q2
6.0 is a tad too low for soil. 6.3-6.8 is recommended. 40 inches with good ventalation shouldn't cause heat stress. Heat stress would also show on the new growth, closest to the light and exposed to the most direct heat.
fishman
Your temps sound good to me. My advice wit hthe little knowledge of your grow that I have is that you are just experiencing natural leaf death. Older leaves will wilt up and die eventually. If you have lots of green then I wouldn't worry about it. as long as there is enough green area to catch light you should be good.
On the other hand if you are having a problem I think it would be either fert burn or deficiency. My instinct says it's natural leaf death though.
4Q2
If he were at 4 weeks of flowering, I'd say you were spot on fish. But at 4 weeks veg'. he shouldn't be loosing leaves.
bonghitter
Hey blackomens666, Are you letting the soil dry out some before you water each time?
blackomens666
The temp didn't seem to high to me either. The new leafs look great, but none of the girls can keep all their leafs very long (small leaf mass), that's why I'm worried. Could RH cause this? I live in a dry area and it is always at about 38-45% the temp has also reached up to 85 in the past for short amounts of time, I put some water and perlite in the room but is as a minimal effect under T-5's. The problem seems to just slowly progress up the plant at about the same rate as new growth. I overwatered them once could this be the problem, it has been about 2 weeks since the foul up and I now wait 5-7 days to make sure the soil is dry, but the leafs are still getting brown at the tips and curling up. I have looked at every possible resource with no viable answers. I also recently used NRS green leaves grow juice for vegetative growth and will do so every other watering unless not advised. Someone please help!!
fishman
True 4q.
Your ph isn't off enough to worry about. That doesn't mean don't shoot for better though. I would say fert burn. How are you ferting? And what are you using?
In 4 weeks I can grow a pretty bushy plant. Bushy enough to block light from the lower leaves.
(Edited by fishman at 7:11 am on Sep. 8, 2005)
4Q2
At 6.0, magnesium, Potassium and calcium are locked out. Nitrogen is barely available. "MY" diagnosis, with information available, is ph problem.
from left to right: (N) Nitrogen (green) (P) Phosphorus (red) (K) Potassium (blue) (Ca) Calcium (yellow) (Mg) Magnesium (purple) (Mn) Manganese (orange) (Fe) Iron (light blue) (B) Boron (black)
Dew Drop
You should flush your soil. If you haven't flushed this might be were your problem is. The fert would still be in the soil so it's kiiling your plant
fishman
Nice chart. I've never had a ph issue. So admittedly it is an area I am weaker in than most. My soil just stays perfect for me. If this is the acse though I would strat with flushing and a re-check. I hate having to flush though. It would also lower the nute levels just in case it is fert burn. Ph is a cheap fix. So it wouldn't hurt to try.
