Please Help Identify Issue / Deficiency

[Hiroln]

Ok, so I posted about this a few days ago and then life got in the way - picking it back up now. So I started these seedlings out in 1 gallon pots using promix HPCC - using Jacks 123 fert. Everything was fine / I then transplanted into 3 gallon pots with Ocean forest soil. Using RO water @6.0 pH for feedings. Most of the plants have been doing fine but last weeks started noticing these brown spots / looked like cal-mag to me. I then stated adding 1.25ml of cal mag to my RO water for the last couple of feeding; but I am seeing it profess upwards on some. I took the run off pH on them / and the ones turning had a runoff pH of ~4.2 - which is real low. I know runoff is not the best measurement / I got a soil pH tester coming in today. Based on that I then increased my pH to 6.8 with cal-mag supplemented in my RO and flushed several times until the runoff pH measure >5.2. This was done Sunday night. There are only 3/4 plants doing this - the rest look fine right now. Any suggestions? If I can’t get this under control I am just going to use this plants as mothers and clone off every shoot I can and start over. Thinking about ditching the ocean forest from here on out and going str8 promix HPCC so I can control things better with the JaCks 123. PPM runoff varied from 300-600 - hence I will prob start adding about 25% jacks to the mix (boosting cal-mag by about 15/20%). Thoughts. All other factors (temp, humidity; etc… have been spot on).

 

[Hiroln]

Forgot the pics - 2 different plants / bubba kush, gelato mix / same issues …. The strain I am seeing issues on are white widow / but not all of the same strain has this issue / just the ones that had the lower runoff pH - the ones with higher pH runoff aren’t showing the same signs. All of them have been treated the exact same way, same watering, same environment, but could have been different bags of OF soil - I didn’t keep track of that.

 

[mysticepipedon]

How often to you water? Does the soil ever get dry?

 

[Hiroln]

ok / so I check the soil - both with a soil meter and slurry test / slurry was in the low 6s - 6.1, 6.2 - soil meter showed high 6s, so I don’t think it was pH lock out - could possibly be over watering - thu they have never welted unless lights where off. I water every 2-3 days. But might have been a little much water none the less.

below pics - soil moisture measurement then ph
One of the plants that showed the deficiency, leaves trimmed, big fan leaves HST down, bud shoots LST out ….

Working on the rest now…

 

[Hiroln]

so - I think I am just going to add a little extra cal-mag supplement 100-150ppm to my RO before I mix the Jacks 123 are maybe the same time as the epsom / and see what happens / can’t see it being anything else at this point. soil pH is fine, a little over watered for sure, temp =72-79F, humidity 40-50%, High LED 2500w cob …. Thoughts?

 

[jguit]

I'm not a soil grower but if things were going well in promix, why did you transplant into a mix of ProMix and soil?

If you're using something like Jack's, it makes much more sense to stick to soilless (ProMix) which require being fed nutrients. From experience, Jack's and ProMix work great together.

Adding Jack's 321 to ocean forest doesn't seem like a good idea. My guess is Jack's in addition to ocean forest soil are burning the snot out of your plants.

 

[mysticepipedon]

It looks like overwatering to me.

Lift a pot full of your dry soil, packed. Then lift the pot with your plant in it. Noticeably heavier?

If so, it doesn't need to be watered again until it's near the weight of the dry soil.

Cannabis is not a houseplant or a wetland plant. It likes oxygen in its soil. If the soil is always wet, its roots don't get enough oxygen.

 

[jguit]

..and yes, overwatering isnt helping things either.

If possible, I would try to take your plants out of the 3 gallon containers, shake off all of the ocean forest and tranplant them back into promix. Otherwise you're going to be chasing your tail if you plan on using Jack's.

 

[Hiroln]

Thanks for the replies - let me clarify, I haven’t used jacks yet after tra panting into 3 gallon containers, only when they were in 1 gallon pot with pro mix - I used the ocean forest bc 1) I got the OF bags for $12 per (ocean forest and coco loco) and new it was a good deal so I figured I would give it a try (got 15 bags a piece). They have been in the 3 gallon pots for about 5 weeks now - reason I said I was going to add jacks is because the Run off PPM is around 300-600 on all of them now, a fresh bag run off is closer to 1800-2000. I think the issue has been a combination of over watering with RO (with out adding cal-mag back) with no nutes and now they need a little more nutrients bc the OF has started being depleted.
Thanks for all the advice…. I have some 5 gallon fabrics pots, so I might try they on the worst ones. Thanks.