Help - brown spots on leaves

[Nepisiguit]

First grow, in soil under COB LED lights on 18/6. Two photos are in veg without any problem. However having some nasty looking discolouration on the leaves of one my Blue Diesel autos. These have been getting GH flora series nutrients following growweedeasys schedule. Tap water PH is 7.1, nutes solution Phs around 6.55. Runoff was at 6.2.
Humidity was a tad high in early flowering, but it’s been at 50% for the last week or so. Just tried flushing with water on Friday.

if anyone can chime in with advice it’d be much appreciated.

[9fingerleafs]

Looks like a very advanced calcium deficiency. It’s odd because the GH flora trio has nitrogen and calcium together and he plant has more than enough nitrogen. Where did you got your coco from? Did you washed and soaked before using? It’s called buffering the coco

[Nepisiguit]

I’m growing in soil, 5 gallon fabric pots

[9fingerleafs]

What a dumb me. I’m very sorry, did not read carefully enough.

[Tersky]

How big are those pots? What kind of soil? It could be root issues as you have serious deficiency issues. How long till harvest?

[Nepisiguit]

They’re 5 gallon fabric pots. Soil started out with a Professional Grower’s mix which included perlite. I topped the pots off a few weeks later with some Pro Mix garden soil and a little seafood compost.

Planned harvest to be about 4 weeks away.

[Rwise]

What I see is a root/PH issue

[Gjourney101]

Yeah only traces of calcium are needed, so your pH could very well be too high or low. I'm assuming it's in the high end.

[SoOrbudgal]

Flush the brown down

[Nepisiguit]

Admittedly I was a bit slack on monitoring ph and watering to runoff early in the grow.

I have my own well and tap water Ph is 7.1 to 7.4. I’m using the GH Flora Series performance pack at 1/2 strength and the solution Ph is around 6.5. I was alternating straight water and nutrient solution, thinking the Ph would land somewhere around 7. I first tested runoff early last week (with the nutes) and it was at 6.1, so I’m thinking I had a build up of nutes at the roots and the Ph was lowish, perhaps contributing to a calcium deficiency? So I initially added water until runoff ph was 6.2, then two a days later gave it a good flush with straight water. Should I consider adding CaliMagic to the mix or anything else? Or do I just keep a close eye on ph and hope for the best?

I just watered the Acapulco Gold photos which are in veg next to the Blue Diesel autos which are about half way thru flowering. They were due for straight water so I adjusted ph to 7, runoff was at 6.5. That seems about perfect, the plants are strong and healthy but a few lower leaves have recently yellowed.

So it seems if anything that my ph is a tad on the low side.

The blue diesel autos aren’t close to needing water again as they were flushed on Friday.

[CaptainWiese91]

If your Ph is on spot. Then I’m thinking you have a lockout.
too much salt building up?
or root issues, but it’s highly connected to lockout issues

[Rwise]

I would add a bit of dolomite (pelleted) to help buffer the soil.

[Gjourney101]

Flushing your soil with pH water should help. Use 3x your pot size. (Example - 5 gallon pot needs a 15 gallon water flushing

[Nepisiguit]

Watered today and thought I’d post an update. I think the theory of nutrient build up and low root ph, possibly with calcium or other lockout is seeming plausible. Things seem to be improving now that I’m ensuring plenty of run off and closely monitoring ph.

Both autos continue to bud nicely. The worse looking one seems to be doing better but still doesn’t look good. Kinda hard to tell since there isn’t much veg growth happening anymore. The other has some discolouration but not as bad.

They each got over 2 gallons of neutral 7.0 ph water with a tsp per gallon on CaliMagic. Runoff Ph was 6.29 on the ugly one and 6.38 on the other. So Ph is slowly trending in the right direction. If they continue to improve I’m hoping to start back on nutes at next watering, definitely keeping a close eye on ph.

Feeling confident I decided to try to scrog / LST one the photos. That went ok until I split the main stem where it was previously topped. Anyways she’s taped up now and will hopefully fully recover. Plucked a few sickly lower leaves, but overall these girls look strong and healthy. They both got 2 gallons of 7.05 ph water and CaliMagic. Run off PH of 6.61 and 6.56. Again Ph is trending slightly upward and I’ll try to keep it in the 6.5 to 6.8 range. They will get nutes next watering. Really looking forward to switching these over to flowering, but they will need to wait for the autos to finish.

I’ve upgraded to an Excel spreadsheet to document watering, nutrients, ph, height etc.. as my notes were outgrowing the calendar.

Thanks for all the responses, I’ll try to keep this thread updated in case others can learn from my mistakes.