Second grow. Same issue

I am growing under COB LEDs. Lights are about 18 inches from plants running them 24/7 for now. I just had to fire up another two rows so I will likely go to a 20on 4off schedule to keep Temps down. Temps vary from upper 60s to low 70s. I am in Happy Frog soil. I am using Aurora Roots Organic nutes. Water is ph 6.5. Runoff seems show ph of around 7 usually. I had some leaves start to show yellow spots with brown centers at week 2 of veg. New growth was fine for a couple weeks then more showed up last week. Plants just finished their first week of flower and are a total of 5 weeks old. I took a pic of the whole plant then a close up of the issue. 3 plants look like they all have either a calcium or magnesium deficiency. The 4th onew just looks to have a few leaves turning a lighter green like theyou are going to yellow. That plant seems to have a different issue.

They just look hungry

Imo i see multiple deficiencies

it looks like you're over feeding your plant

Sweet. 2 replies that perfectly contradict each other. I'm following the recommended feeding schedule for the roots organic stuff. The seed company does state these plants use alot of nutes.

What kind of water are you using? Filtered? Tap?

I am using a hydrofarm hydrologic gogreen filter. And I usually let the water sit for 24hrs after I filter it.

Quick question about nutes. I have been letting the water sit for 24hrs then for feeding adding the nutes and then adjusting the ph. I just read I should mix the nutes then let them sit 24hrs before feeding. So no my question is do I adjust ph right after mixing nutes then wait 24hrs and feed? Or do I mix nutes then wait 24hrs then adjust ph and feed? Thanks for the help so far. I'm just hoping I don't have such a poor yielding harvest this time and want to figure out what's what before it gets to late.

you need cal mag and nitrogen ....feed her

I fill up a bucket and add nutrients and pH the water last.

Whats the reasoning for letting it sit out?

Supposedly with just the water the chlorine or whatever else is in it evaporates out.

And I read that after mixing the nutes up you wait to let the ph stabalize. I just don't know if you are supposed to adjust it right after mixing or after letting it sit.

Looks hungry to me. I add nutes then pH last, next day check pH again to make sure it's stable.

I apologize for my mistake, I thought it was a nute burn because of the tips on some leaves are curled up and dry.

TAGrows said:

Supposedly with just the water the chlorine or whatever else is in it evaporates out.

And I read that after mixing the nutes up you wait to let the ph stabalize. I just don't know if you are supposed to adjust it right after mixing or after letting it sit.

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Id wait a couple minutes to make sure the pH is settled. But a whole day? Seems excessive.

Ive never had issues in the 5 years ive been growing.

And the bad thing about the internet is everyone has an,opinion and sometimes they differ. This is a clearcut hungry plant. You wouldnt have light green fan leaves if you were overfeeding to the point of burning. They would be dark green. Light green tips is. K deficiency. Brown between veins is magnesium def and the uniform light green leaves are nitrogen def. Soon they will yellow and fall off.

If youre feeding full strength it could be a pH issue. Shoulsnt be running into def with a manufacturers full strength.

Thanks for all the help. I got some of the roots elemental which is their calmag. 20% calcium 2% mangensium. Seems like a great ratio for calmag.

I will continue to check my runoff ph. If I am watering with ph 6.5 and my runoff is roughly 7 my root ph is too high. I am thinking I should water at 6 until my runoff is lower. How close should runoff be to the water your watering with?

Another vote for needing higher nutrient concentrations. Looks to me like your using pro-mix? I tend to run into nutrient deficiencies growing in pro-mix when my plants get too root bound and consequently dry out too much too often. Just a thought.

Fed them today at around 6pm. Feed was at 6.2 ph and runoff was at 7.1 or 7.0. Just got home about 5 hrs after i fed and looked at them. A few leaf tips look bright yellow like they got nute burn. Ugh.

Buy a ppm meter, then you will never be guessing how strong a fertilizer solution you are applying to your plants. I run a ppm between 600-1200 depending on the stage of growth. $30 on Amazon.

Coloradoclear said:

Buy a ppm meter, then you will never be guessing how strong a fertilizer solution you are applying to your plants. I run a ppm between 600-1200 depending on the stage of growth. $30 on Amazon.

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TAGrows said:

Sweet. 2 replies that perfectly contradict each other. I'm following the recommended feeding schedule for the roots organic stuff. The seed company does state these plants use alot of nutes.

Click to expand...

TAGrows said:

Thanks for all the help. I got some of the roots elemental which is their calmag. 20% calcium 2% mangensium. Seems like a great ratio for calmag.
I will continue to check my runoff ph. If I am watering with ph 6.5 and my runoff is roughly 7 my root ph is too high. I am thinking I should water at 6 until my runoff is lower. How close should runoff be to the water your watering with?

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Good advice from Coloradoclear.

I'm going to tell you that you are chasing your tail testing run off PH. Do you believe me TAGrows?
Someone else is going to give you an answer like:
Yeah it should be close or a little below the PH of the water going in. You may even be blessed with advice on how to fix the problem if the runoff ph is to high or to low.
Which one will you believe?
What is your game plan to confirm which answer is more correct. Ask more people on forums? Go to your favorite marijuana book that has been heavily researched?
I'm betting on A.
What books do you own?
I've been reading this thread and was not going to bother commenting figuring my response would get lost in the garble. Then I thought this approach might work.
Buy a good book if you don't have any. Good Luck!

Coloradoclear can you suggest a particular make and model?

Is there another way I should be using to figure out root ph?

Buba that is exactly why I have been reluctant to post on this site looking for advice. Sometimes though it's better to just ask for help. Isn't that the point of this forum and sub forum? Did I assume incorrectly that there would actually be competent people on this forum that are willing and able to help? At this point I'm 5.5 weeks in to a grow and would prefer not to do trial and error testing and destroy an entire run or have another modest yield. Oddly enough I haven't taken any of the advice yet and put it into action. I did buy calmag, but that was my plan before I even posted from doing research on what my plants were displaying as symptoms. I was very surprised to see some nute burn after last night's feeding as I had not seen any yet this grow.

I have been reading some what I thought were pretty complete online books/tutorials. I have no problem picking up a book and reading it. Can you suggest a good read? Even after that with my lack of experience I will likely have my doubts on if I am doing things right. Confidence in your abilities takes time and familiarity.

TDS-4M by HM digital, $18.00 on Amazon