Blistering on leaves/ yellow veins

[mbeers6]

Looking for help on what is causing the issues below and how to correct it. Following Chris’s seven steps as this is only my second grow, first time for photo period plants.

1. strain- ilgm gold leaf feminized
2. 3 weeks into veg. No NUTES have been fed yet
3. soil – FF ocean forest in 5 gallon pots. Started in solo cups, then 1 gallon pots.
4. water -RO PH’d to 7. Water when pots feel light
5. lights – 2 electric sky ES300 in 4x4x6 tent.
   PAR is around 450-500
6. small fan circulates on low
7. ppm during run off test was 1,500 to 1,650 for all plants. PH was 5 (I know it was low)
8. no cal mag yet (maybe this is issue?)

all plants seem to have yellow veins on leaves and blistering. Tried to research this and my guess is either a magnesium deficiency, or maybe windburn?

any ideas?

Leaf tips also curling down so maybe soil has too much Nitrogen?

[mrgrowit]

This post was stuck in pending; sorry about that. I don’t know why that happens.

Thanks for post the details on your grow; it makes it a bit easier to help diagnose. Looks identical to magnesium deficiency. Here’s more info on it:
https://mrgrowit.com/post/magnesium-deficiency-in-cannabis-plants/

Do you have CalMag on hand?

Edit: Also could be pH fluctuations causing it. More info:
https://mrgrowit.com/post/ph-fluctuations-in-cannabis-plants/

[mbeers6]

Thx Chris! I’ve been watering with 5ml of cal mag per gallon of water but only since 1/2/24. should have started earlier with LEDs I guess.

2 days ago started spraying leaves on one plant with epsom salt mixture.
Run off on last watering (1/7) read 1,310 PPM and PH of 6 (other plant was 6.3). Incoming RO water after adding cal mag had PH of 7.2.

I bought dolomite Lime, maybe add to top of soil before watering to get PH up?

Final question, these have been in veg around 5 weeks. I’m worried about stretch and tent height. Think I should wait until yellowing in veins issues resolved or flip next week or two?

[mbeers6]

[mbeers6]

Close up of leaves as of today

 

[mrgrowit]

Dolomite lime can help adjust the pH, but dialing in the right amount can be tricky. I’ve heard too many horror stories where dolomite lime was added and the pH swung too far and they couldn’t get it back in range, so I personally avoid using it. But with a runoff pH of 6 and 6.3 like you mention, it doesn’t sound like there’s a really need for it imo.

You could top, super crop, and/or LST to help control height. I’d wait to flip until I see new growth that appears healthy.

[mbeers6]

Thx for advice Chris, think I’ll skip the dolomite and continue higher PH going in.

I did top all plants. Hoping the new leaves look good ASAP.

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