Thread: Tips of leaves look burnt

Grown in soil-less mix, the tips of some plants look to be burning (rust colored) and curling upwards. Using this site Revised: The Complete Guide To Sick Plants,pH and Pest Troubles - PlanetGanja.com (quite helpful) I have been trying to diagnose my issue and I believe I've narrowed it down to potassium or calcium. The issue isn't too bad yet, and it mainly seems to affect the lower leaves. I will try to get pictures up soon, anyone with any experience, please help!

Heat stress maybe. Fill out the form.

I don't think it's heat stress, because temps are not that high and plants are not that close to the lights. Other than the burnt tips, they actually look good (to me, which might not be saying much).

I don't really understand how this form works so I shall do my best:

H= hydro - Fafard's potting mix with extended release ferts


E-indoor
E-soilless
E-Fafard's Container mix (extended release ferts)
SCL- about 20% perlite
SCLR-Soil or slab runoff pH
E- tap water, pH 7 plus or minus .2
E- plants 5 weeks old, 9 days into flower
E- Botanicare Pro Grow (during veg), Pro Bloom (now), Sweet and Liquid Karma (since the beginning)
E- watered about every 3 days
E- 138watts of CFL, about 3" from tops of plants
E- ambient temperature is usually 70-73F
E- having trouble with humidity, usually 60-70%
E- 12/12
E- computer fan for circulation
TR-Did you pre-soak your media in pH corrected solution? no

Within the next few days plan to add a few more lights, and a bathroom fan to help control humidity levels (and possibly temp. if that becomes an issue with increased lighting). Also, I didn't read runoff pH last time, but the time before that they were lower, about 5.5, so this last watering I added some pH Raise.

sounds like the being a little over fed. try to feed them 1/2 strength.. less is more imo..

The last watering they received was at 1/2 str because I switched from Fafard's Potting with no ferts to Fafard's Potting with ferts (I didn't have a choice on that one)

Originally Posted by fasts102376

sounds like the being a little over fed. try to feed them 1/2 strength.. less is more imo..

Classic sign of over fert = burned tips. Don't feed for a couple waters or cut to 1/4 strength.


Good Luck

Originally Posted by LolaGal

Classic sign of over fert = burned tips. Don't feed for a couple waters or cut to 1/4 strength.


Good Luck

I will do this. In the mean time, if anyone would like to respond to this thread, NPK values, and help me understand how I'm over fertilizing them, it would be very helpful. Thanks!