Hey all! Long time lurker and big fan of the forum. I try and keep any questions to a minimum and research everything best i can before asking others for help but im a little stumped with this issue. I usually grow once or twice a year and have been growing autos up until this most recent grow. Growing a standard plant has allowed me to experiment keeping my plant as healthy as possible before switching the lights (which i haven't done for years, thinking that autos were the easy option).
However for this and every auto grow i have undertaken over the last 5 years i run in to this same issue, using the below setup:
Setup: DWC, Orange hill special, 400w leds, gh nutrients - ec 0.4 to 0.8, ph 5.9 left it drift down to 5.2 before adjusting. Humidity 50 to 60%, temps lowest 24c highest 28c. Rez temps 18c to 22c. Change rez once a week. In grow tent, temp controlled using thermostat. I’m supplementing with ¼ spoon epsom per gal, and small amount of silica. Plant is 10 weeks in veg.
Problem: Plant showing zink, mag, calcium, iron def.
I keep my ec on the low side but my leaf tips looks very very slightly bunt. If i up the ec the deficiency seems to get worse and the plant looks less healthy. Reducing the ph doesnt seem to make any noticable difference. I can’t seem to solve the puzzle.
Possible reasons:
However for this and every auto grow i have undertaken over the last 5 years i run in to this same issue, using the below setup:
Setup: DWC, Orange hill special, 400w leds, gh nutrients - ec 0.4 to 0.8, ph 5.9 left it drift down to 5.2 before adjusting. Humidity 50 to 60%, temps lowest 24c highest 28c. Rez temps 18c to 22c. Change rez once a week. In grow tent, temp controlled using thermostat. I’m supplementing with ¼ spoon epsom per gal, and small amount of silica. Plant is 10 weeks in veg.
Problem: Plant showing zink, mag, calcium, iron def.
I keep my ec on the low side but my leaf tips looks very very slightly bunt. If i up the ec the deficiency seems to get worse and the plant looks less healthy. Reducing the ph doesnt seem to make any noticable difference. I can’t seem to solve the puzzle.
Possible reasons:
- ec to low - but why would the def get worse with a higher ec and why am i seeing tip burn?
- Plant has a phosphorus lock out which affects iron, zinc and calcium uptake - maybe i should flush, but with a low ec and semi stable ph why should i have a lockout? I have yet to flush the plant.
- I once read that pupming a lot of air in prohibits iron uptake im using a 20l/min @ 0.2 bar pump. Could this be a problem.
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