Yellowing Issues

Hey all.

I have a new room setup and some issues with yellowing. Starting mid leaves it appears. They are about a week into flower.

Its a sealed room running co2 at 1100-1200 ppm (using controller). I have low to mid 80's canopy temp. Keeping it at temps of about 70-72 with lights out. Currently I am keeping it at 55 percent humidity with lights on and 45-50 with lights out. I am able to adjust humidity anywhere from about 45 up to 80+ if wanted/needed. As of now I am venting 5 times a day for 20 minutes each. when lights come on and then every 4 hours and once in middle of lights out.

I am growing in canna coco using canna coco nutrient line.

I started at 1.3 EC and have since upped it to 1.6 EC (RO water)

PH is currently at 6.1. I started it at 5.9.

Started with

350 A and B
200 Cannazym
75 rhizotonic
125 cal mag plus
100 silicia

I have since added an additional 100 ml of A and B and additional 75ml of cal mag

I don't start using boost until flowers start appearing, around day 14-18.

Idea what may be going on? This is the 2nd grow in this new room and I had very bad yellowing issues with first run as well. I was not running cal mag or silica in that run. That is why I have started using it this run to see if it happens again.

Thanks for any info.

your plants look hungry, but its hard to tell under that light, they look light green ?
from what i can see, i would raise the ph to 6.4 for a few days to allow better uptake of cal/mag, see if that helps, what is your background EC (no nutes)

bobtokes said:

your plants look hungry, but its hard to tell under that light, they look light green ?
from what i can see, i would raise the ph to 6.4 for a few days to allow better uptake of cal/mag, see if that helps, what is your background EC (no nutes)

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I am using RO water, its 1 ppm/ 0 EC before nutes. Those pictures are taken through those blue sunglasses so it does not look so yellow with HPS lights on. They look pretty accurate though to real life. Besides the yellowing leaves it looks a decent shade of green I think.

Looks kinda like nitrogen to me. Is there any N in your bloom nutes?

dtl420 said:

Looks kinda like nitrogen to me. Is there any N in your bloom nutes?

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I am using canna coco a and b, just started using it last run. I did purchase nitrogen boost from house and gardens the other day because I was wondering if I needed more nitrogen as well the first few weeks of flower.