HELP! Yellow dry leaves & spots

[JStryder249]

Using an optic led cob light. Coco coir in 3 gallon smart pots. Following nebula haze coco coir nutrient schedule (general hydro trio with Cali magic). These plants are in the preflower stretch I’m pretty sure. I’ve been going off the weight watering technique. Lights are 28 inches from top of tallest plant. Temp 73-77° humidity between 50-60%. I thought the problem was Nute Burn. But it can’t be. I’m following this exact schedule. I know the ph is no higher than 6.5 and no lower than 5.5 more around 6.0-6.5. It’s getting calmag with every watering. I saw what I thought was algae and figured I was over watering. But I’m not even getting runoff. I have no idea and need help. This is my first grow. There doesn’t seem to be slowed growth except maybe on a couple plants

[Mr.furley]

HI JStryder249
looks like a root problem from the look of it and what your saying.
You should be watering to runoff everytime you water and let your pots dry out till lite when lefted. How often do you water?
the other thing is your Ph, somewhere between sounds like you don't know what it is? Plants in Coco benefit from keeping your pH between 5.8 and 6.3. Id collect some water when you water to run off and check it.
good luck

[ZigZag]

Looks like a deficiency to me, but that can be difficult to determine. If its a calcium or magnesium deficiency the problem could be that your PH isn't high enough, at least at times. Even if you are feeding them a cal/mag supplement if the PH is consistently below 5.8 the plants may not be able to utilize the cal/mag because its best absorbed at PH 6.0-6.5. I grow in coco too and set my PH at 6.25-6.5 at least twice a week. My coco mix is very aerated so it drains pretty fast. The downside is I have to water 5x a week but the up side is it keeps everything moving along without any buildup of salts or nutrient lockout. I'd follow Nebulas flush tutorial and monitor ph in and out and if you have one measure the ppm going in and out too, that way you can get an idea of whats going on inside the planter_whats getting used and whats not. If your PH going in is 6.0 and coming out at 7.0 then you should flush. If the ppm of your drainage is higher than what is going in then you have a nutrient/ salts buildup and need to flush. Flushing is a PITA but its saved my butt more than once! I'm using liquid organic nutrients in my present grow for the first time and my plants are happy... so I am too. No issues with any PH or root problems, no issues with excessive or deficient nutrients either. I hope you get this resolved soon. Best wishes for 2019!

[JStryder249]

I use the ph test kit with droppers so it’s gotta be fairly accurate. But the last I had runoff it was much lower than what was going in. So then I flushed. I grew quite a bit and been. Then I watered it with nutrient water and I saw the problems again. I have a ph meter but I’m waiting on calibration liquid. I also have a tds meter coming. What ppm am I looking for?

[Mr.furley]

Your PH going in and out Should be 6.2 to 6.3 and your ppm should be around 800 to 1000 going in on feed only.
Do you feed then water only or have you just fed since your last flush?

[ZigZag]

Get those meters and follow what Mr.furly suggested. That should get you back on track. I used to flush with plain water PH 6.0, but now I flush with 1/2 strength nutrients and it seems to work better if I need to....seems to balance things out more completely than when I flushed with plain water and then added nutrients with the last watering. But that might be the aerated coco I'm growing in too....

[JStryder249]

What does it mean if the ph coming out is lower? I do have the 70% coco and 30% perlite mix. I was feeding them with plain PhD water but still calmag in it every other watering. Then I tried watering less but more often. I was just feeding after the last flush. But once I saw these symptoms I gave them plain PhD water. Yet I didn’t give enough for runoff. Judging from the size of the plants they need more than just few cups of water. Their roots gotta be doing fine cuz I can see a few poking out the bag. I really appreciate y’all taking the time to help me. Happy New Years to both y’all

[Mr.furley]

Hey! No problem JStryder and Happy new year to you.

"Then I tried watering less but more often" "Yet I didn’t give enough for runoff."

And this is your problem! You need to water to runoff every time, let your pot dry out and repeat.

This just give your plants less more often is some of the worst advice I have heard being give to new Growers!

https://www.growweedeasy.com/how-often-water-marijuana

I grow in Coco, been doing it for Years now, never water more then twice a week.
For a 5 gallon fabric pot I mix 1.5 gallon water and my nutrient, PH to to 6.3 and water till it trickles out the bottom, soak the whole pot!
About 3 days later, after the top 2 inchs is dry and the pot is lite when I pick it up, I ph 1.5 to 2 gallons of plain water per plant. And that's it!

You can collect the first little bit of water that trickles out and check the PH, if its way off you have nutrient lockout and need to flush.

My current grow is in my post signature below, this link is to my last grow with how I water plant.

https://forum.growweedeasy.com/forum...aze-revolution

[ZigZag]

If your PH is coming out lower than when its going in then its probably picking some some acidic salts on the way out. Wouldn't hurt to give it a good flush.if your roots are looking good then that should do the trick.
How often you water depends on how fast your medium drains, how much air circulation moves through it, how much water and air are retained by the medium, and how large your planters are. Not to mention how large the plant is, how much air circulation there is around the plants, and the humidity. All these affect evaporation and how much water the plants take in.

Your mix of 70/30 is not nearly as aerated as mine (only about 40% coco) so you probably only need to water once every 2-3 days, But when they get bigger, with more large leaves, since your in a 3 gallon planter you'll likely need to increase the amount you water. Plants with lots of large fan leaves will use more water too. In your case I'd start by letting the top inch of medium dry and then use the "lift the pot method". I use the "lift the pot method" to decide if I need to start increasing the watering schedule.

What I've found out working in coco is that the aeration in the medium is crucial_ you need to water accordingly. A more dense medium like the 70/30 your using is going to drain slower and hold more water than the aerated medium I'm using. The more fine particulate matter also absorbs more water and after you've been watering it for a while those fine particles settle down through the medium to the bottom of the planter, which also slows down how fast they drain. Ever wonder why your perlite "works its way to the surface"?
Its really not...the fine particulates are just settling and since the perlite is course and very light in weight it doesn't_ so it seems that its working its way to the surface when its actually just sitting there.

This isn't to say that you need to change your medium_ you just need to find out what works best for what your using. It took me about 6 coco grows until I settled on a mix I liked best.
And when you flush you need to run a lot of water through those planters. If you're only giving them a few cups then try running a gallon or so through one and see how much runoff you get... wait an hour and if your plant isn't dropping run another gallon through. And so on. Once you've run 3 gallons through they should be pretty well stabilized. Once you get more than 30% runoff your coco has absorbed just about all the water it can and the planter will be as heavy as its going to get. Use that as a base for judging how light it gets after a few days of no watering.

Cheers!

[JStryder249]

Thanks for all the help. I really do appreciate you two. Especially taking the time to respond with thoroamd detailed messages. I know it takes time out of your day and may hurt your fingers. For that I am truly grateful. I’m going to take all this advice. I think I’ll flush them real good. I’ll make another post to show my progress

[ZigZag]

That's what GWE is all about_ sharing information and experiences. Great people to talk with and a ton of knowledge. There are a lot of growers using all kinds of setups so you can always find someone who can lend a hand, answer a question, offer suggestions, whatever_ there is no "best way"_ only the one that works best for you and your plants. Cheers and keep us updated. PS: My fingers only get sore when I'm cutting fan leaves on the backside of a plant by feel rather than sight... and clip the end of a finger instead of a stem! Downside of keeping your trimmers sharp, yeah.

[alltatup]

ZigZag Mr.furley AMEN. And good luck JSTryder: you got good folks helping you (I'm hydro ;-})

[JStryder249]

What ph and tds meter do y’all recommend?

[Mr.furley]

Blue lab is the industry-standard, expensive meters.
I personally use the 10$ ones off Ebay with no problem.

[ZigZag]

I'm using the Blue Lab_ no choice for me, only ones they had and I needed them fast so had to get them at our only grow store. The first PH meter worked well for a year and died. The second one has been going strong for the last two years and so has the tds. But they are pretty spendy.

[ZigZag]

I probably killed the first one myself by not checking on it during a period where I didn't grow for about 3 months. Just make sure you clean them after each use and keep the inside of the caps moist with the 4.0 test solution or water's ok too.

[JStryder249]

Yea I guess I’m gonna have to put a piece of sponge in the cap with the solution bcuz it’s already been buggin out a bit. My tds meter seemed a bit off as well. Do you guys have any social media like Instagram or a YouTube account I could follow and possibly get advice directly?

[Mr.furley]

This is the best place to get help from Me. Do you have calibration solution for your TDS meter?

[ZigZag]

No type of social media related these interests for me. My work takes me out of range of convent interest access at times so then everyone would get bored and I'd lose all my followers_ haha. I have trust issues with open media platforms like that too. I also suggest the calibration fluids_ the #4 and #7. I prefer the bottles rather than the envelopes.

[JStryder249]

Yes and for the ph meter

[ZigZag]

Shoot, well if you have the fluids thats not a great sign then. When my PH meter failed it was just a year old but the grow store replaced it anyway. Got lucky... but then I'm a good customer.
Have you tried cleaning the sensors with dish washing soap and warm water_ use a soft toothbrush to clean and then rinse? Worked for me so far...

[JStryder249]

No but I’m definitely gonna give that a try. I haven’t even had either for that long. So as you can imagine I’m pretty disappointed

[Mr.furley]

I just use the calibration solution bag to store my meter in when it's off. I turn it on and sometimes need to move the screw, the meter needs to be put in clean water and gently move up and down to remove calibrations fluid before using. I replace the fluid from time to time.
What meters did you get?