Yellowing problem, cannot figure this one out

**chrononzon** · 03-02-21, 02:33 PM

Hi folks,
I have a few RQS Royal Gorillas in Biobizz Lightmix in fibre pots in a 120 x 60 tent.
7 wks old, temp 24 c, humidity 65%
light is a migro array 240w.

Plants have started to get yellowing with green veins.

At first i though the light was too close but I have followed instuctions to the letter.

I'm fertilising with Biobizz Grow at 4ml/litre every 2nd water.

Really bamboozled.

see the yellow leaves have green veins.

the plants have been over watered and underwatered a few weeks ago as part of the learning curve

Would anyone care to offer thoughts?

thanks

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**Herbitual** · 03-02-21, 02:36 PM

Any info on the water you're using?

**chrononzon** · 03-02-21, 02:42 PM

it's just tap water thats poured 24hrs prior and left to room temp which is 22

**Herbitual** · 03-02-21, 02:53 PM

If I had to guess (that's really all I have) I'd say the over-watering has created a problem in the root zone (too wet to allow uptake of nutrients) and that as a result you have a magnesium deficiency...as I say - pure guess work.

**chrononzon** · 03-02-21, 03:17 PM

very interesting.

However we are now careful to have a good wet-dry cycle. They are currently definitely not overwet!

I have some cal-mag supplement . i wonder if I should use some!!!!mmmmm

**Herbitual** · 03-02-21, 03:19 PM

I think at this stage, I'd be spraying the leaves with a very weak calmag solution rather than adding it to the feed...again, purely my own preference.

**chrononzon** · 03-02-21, 03:20 PM

problem with this cal-mag theory is that yellow leave with green veins is normally lower leaves!!

This is upper leaves..mm

**chrononzon** · 03-02-21, 03:31 PM

thanks for the thoughts. it's worth considering for sure.

Just a bit concerned that the lower leafs are not doing this

**Karsa** · 03-02-21, 03:59 PM

That's either Potassium or Magnesium deficiency from what I can see in ops pics.
Are leaves drying at tips/ edges or curling at all?

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