❌High ph runoff❌

Hey guys

currently in week 6 of flower and I’ve noticed two of the 4 plants in my 4x4 starting to turn lime green and claw. the first thing I done was flush them. no Matter what I done my runoff ph was 7.3-7.5 even if I was tipping in 5.8ph it would still come out the same. the soil it a coots recipe that I built with top quality casting and compost. i bought a bottle of liquid sulphur to try and lower it but just thought I’d ask if it’s the right thing to do or not before I do it. pretty sure my problem is a sulphur deficiency. or should I just water in some Epsom salts? I’m assuming there’s a huge buffer in my soil with all the organics.

It’s my first so grow any help would be much appreciated

thanks.

10 comments

Comments (10)

Thole380

Sep 25, 2022

I think you’re onto it with the light. Yeah I’m running a QB 🤦🏻‍♂️ Biggest rookie error. I’ll be buying a spider farmer SE7000 after this run. In the affected area the ppfd is ranging from 800-1000 ppfd and 38-40 DLI (I’m not supplementing c02) so definitely well on the high side. ambient co2 sits around 450 ish.

i have the height to go up so I’ll lift it and see what happens. I wish I stuck with my gut feeling from the start and stayed with the light being the problem rather than stressing the shit out of them with all flushing it did. good learnings though 😏

Will the two other plants suffer not getting as much ppfd if I raise the light up to fix the tall plants issues?

@Cam Z

Thole380

Sep 25, 2022

Replying to

That’s fair enough. just thought I’d ask the question. it’s always cool to see other peoples setups and grows.

ill Definitely have a read over your posts, the light building is super cool.

thanks so much for steering me in the right direction I really appreciate it.

cheers from down under

🇦🇺 🦘✌🏼

Cam Z

Sep 25, 2022

Replying to

Happy to help. Looks like you are in for a good harvest in the near future. If you have any other concerns you know how to summon me. Hope your bud is stronger than this guy.

Cheers!

Thole380

Sep 25, 2022

Replying to

Hahaha thanks mate 😁

Cam Z

Sep 24, 2022

That ph is fine for soil. You shouldn't flush with organics or water to runoff usually. The biology in your soil is probably altering the ph of your soil because it makes it more conducive to their development. Is the growth a bit further down those plants still green? It appears that way in the picture. Could be a bit too much light. Is that tip burn old damage or is it progressing? Sulfur deficiency typically starts on older leaves first even though it is immobile. You could make a tea with nitrogen heavy earthworm castings (not all castings are the same) or you can hit them with a dose of synthetics to get them over the finishline.

Thole380

Sep 24, 2022

Replying to

from the start I’ve been feeding them a light dose of green planet synthetics as well. (The full dual fuel range) in week 6 flower I’m at 1/2 dose. (water, feed). I kind of thought nitrogen as well but the lower growth is still a good colour and nitrogen is obviously mobile so that didnt really fit the diagnosis Imo . the yellowing top and clawing really only pointed to sulphur deficiency to me. light was also the first thing I thought because it started on those two plants closest to the centre of the ligh with the tallest buds. I lifted the light a couple of inches and dimmed it a bit but I didn’t seem to change over a few days. I’m spewing the grow was going pretty well until now.

Cam Z

Sep 25, 2022

Replying to

I think you are being too hard on yourself. The grow is still going very well from what I can see. I'm about 99% sure it is too much DLI based on the pattern and your reply. It was hard to see the lower growth in the pictures so it was a toss up with nitrogen or light. If you already raised the light some then you are moving in the right direction. I might pull it up about 6 inches or so if you have the room. Do you have a qb style light? You can also cut an hour off the cycle to reduce dli if you don't have the space to raise the light (most newer growers don't think of that). You can pull off some of the more damaged leaves to let the undamaged leaves below the top layer get light instead.