Can anyone tell me what deficiency this is ?

Hi , I’m new to growing have this gorilla glue auto in 4th week flower , a week ago it started showing some discoloration and rust spots on the leaves a few leave have also yellowed and died , any help ?

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Moe take a look at this chart and see if you can make a match, I'll look too. Click the chart to enlarge.

how much have u been feeding in ec.

What medium? Can you check EC, PPM or PH.
What nutrients?

Without knowing those factors it’s hard to be much help.

That said, it looks to me like it could be a combination of calmag deficiency that may be causing problems with phosphorus uptake.

Hi , sorry guys for incomplete info , using Organic super soil , soil ph is 7.5 , watering with RO water , been top dressing with worm castings and insect frass every 2 weeks , also using cannabis microbes consortium.

Twohearted said:

What medium? Can you check EC, PPM or PH.
What nutrients?

Without knowing those factors it’s hard to be much help.

That said, it looks to me like it could be a combination of calmag deficiency that may be causing problems with phosphorus uptake.

Click to expand...

, using Organic super soil , soil ph is 7.5 , watering with RO water , been top dressing with worm castings and insect frass every 2 weeks , also using cannabis microbes consortium.

That is high ph even for soil, 6-6.5 is a better range for soil ph. At 7.5 you are getting into lockout territory for a number of micro nutrients. Also unless your tap water is really bad you might be better off just using tap water to make sure you aren’t missing out on all the micro nutrients in tap water. Everyone always rushes to RO thinking it will always be better, but most tap water is usually just fine, sometimes better even.

Try watering some water adjusted to PH of about 6 and flush a few gallons through your pot. You can use RO but you might need to PH it lower to get the soil PH where you want it. Since RO water has nothing to buffer it just a few drops of PH down will make the PH go down a lot, but when you add it to you soil that has a lot of buffering elements it will have little effect and the water PH will basically get canceled out by the soil PH with more dissolved solids that buffer the PH.

I hope this helps.

Thanks , I will try using tap water , it’s good enough for us to drink so I assume it wouldn’t hurt the plants ? Will just let the chlorine evaporate, if I ph Ro water to about 5.0 would that work?

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Too low Moe, 6.5 - 6.0.

Yes, just evaporate the chlorine over night.

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