First time grower, start of week 7 of flower, help diagnose leafs please

Any idea what's going on? Closet grow(with too little light, going to upgrade next time). Growing in coco, only using basic 3part nutes + calmag

Kuruth,
They don't look bad. Just that spotty yellowing?
What doses on the nutes and calmag?
JD

kuruth said:

Any idea what's going on? Closet grow(with too little light, going to upgrade next time). Growing in coco, only using basic 3part nutes + calmag

Click to expand...

some of the leaves looks really dark green and glossy - could be calcium toxicity leading to a lockout of K, possibly that is what happening to your leaf edges

so possibly you are using too much Calmag, whats the reason for use in the first place?

thanks for the responses

I was under the impression from watching many YouTube videos that when growing in coco coir that I needed to use CalMag. I used the full CalMag dose of 1 teaspoon per gallon and I used a half dose on all my 3-part nutrients(it calls for 1 teaspoon grow/2 teaspoon micro/3 teaspoon bloom per gallon - so I cut that in half.. but it is possible I was adding too much water since I was just sort of winging how much I actually poured on. I am using 8 gal pots.

I'd like to mention I am growing 3 plants, all from different feminized seeds, and the other plants are completely healthy. I checked the PPM run off and I was definitely over feeding. My tap water comes out religiously at 150ppm and when I flushed them with a PH'd tap water of 5.8, the water came out at roughly the same PH but the PPM's on this plant came out at 1150ppm. So I have flushed them a bunch and now I have the PPM runoff of my 150ppm going in- down to 180ppm coming out, but now flushing doesn't seem to be removing the last little bit of buildup.

What now? Just flush until my runoff is proper and keep doses down? Will those markings ever go away.. or as long as new ones aren't showing up I'm fine?

Kuruth,
Sounds to me like you're doing good. Sometimes when growing multiple strains, you'll get one with radically different requirements. I'd jack up the calmag for that strain that's showing the yellow spots. All the spots are between the veins and looks like it could be early Mg deficiency. Keep the others the same obviously. Just a guess really but it won't hurt anything...may help.
JD

It doesn't look that bad, just slightly over-fed. I think it will be fine now

Yosim is thinking too much CalMag.
JD is thinking not enough CalMag.
Natureboy thinks generally over-fed.
At first when I looked at Jorge Cervantes diagrams, it seemed most like Manganese excess.

My novice photography skills are not helping. Here are a few more pictures today, some with the grow lights off.. I have only given them PH'd water for 3 days now.
And there are new brown tips now. I also included one pic of closet from outside, it might help to have a feel for the room. I keep my daytime temps at 25celcius and my night temps at 20celcius, humidity fluctuates between 45-65%. I have a exhaust fan that runs 24/7. I grow in the basement and have just ordered a Co2 meter since I suspect the level to be quite low.

K,
Forget my epsom salt suggestion. Now seeing the tips...looks more like an early nute excess. When you get medium loaded with nutrient salts...you can lock out other nutes too. So follow Natureboy's idea and back off on feedings a bit. Also water to excess...maybe 20% runoff so this doesn't happen again. (preferred coco protocol)
JD

Sounds good, thanks. I'll continue my feed/water/feed/water schedule and I'll just dial back the nutrient potency on feed days. I always feed to 10% runoff and I plain water to 50% runoff. That's why I had stopped checking PPM of runoff, I assumed the heavy plain water every second day would keep it clean.

Man they should cut the dosage in half on back of nutrient bottles.

I'll be back with an update after I see changes, for better or for worse. Thanks again!

Kuruth,
Buddy of mine has been schooling me on coco. I used it but didn't really understand it. You know how people pre-buffer coco before using? Usually low strength nutes and calmag. Anyway...when you give water only...you kinda strip the coco of that buffering. Better to feed every watering. Too late for this grow...but this is what the experts do.
Don't want to let it dry out too much either. It isn't soil.
JD

Interesting JohnDee, very interesting.

I wonder if this buffering is why I had to run so much water through this coco to get my PH to finally run off the same as it went in. I seriously must have run 50 gallons of water through each of these 8gallon pots before the PH ran off correctly.

Wouldn't it be better to just get non-buffered coco and be in control?

I just found this website recently so, time to check out the coco forums I guess.

Morning Kuruth,
No---if you buy non-buffered coco...that just means you would have to do it yourself. If not, then you get all the issues that newbies have in their coco grows. Excess nutrient cations blocking uptake of others. It's the high cation exchange capacity that'll mess you up.

Prawn Connery is a serious coco grower who has used the stuff for over a decade. Read some of his threads. I also got an Aussie link from a member...but can't find it at the moment. But I'll get it to you. It explains things well.
JD

PS No it wasn't the buffering...you had already washed that out. It was the high cec that was holding on to things.

Kuruth,
Here's the link I promised. It's from Canna Australia

http://www.canna.com.au/growing_on_coco_busting_the_myth

Thanks friend.

According to this guide, which seems legit.. you would never flush coco ever. I'm wondering if the run off from coco is misleading then.. it seems like since its buffered it might mess up the ph/ppm coming out.

Kuruth,
When you test runoff, you are (or should be) doing it with regular nutrient watering...or if you're dealing with an overfeeding/nute lockout mix up a batch of 1/4 strength.

Point being that it's only a guideline. compare what's going in to what's going out. Say your feeding at 500 ppm but runoff is 2000 ppm. That's extremely useful info. Your rootzone is toxified.

The goal with a 20% runoff with every feeding is that you will never toxify your rootzone. It is preventative. No real need to check runoff.

Really experienced growers with many coco grows can use runoff numbers to gauge the next batch of nutrients (up or down). But those guys are few...and I'm certainly not one of them.
JD

Quick respons there JD, much appreciated.

Do you know why watering to 20% runoff prevents toxicity in your root zone? Would watering to 50% be just as good but just be wasting more nutrients? I think this clarification could help me.. does watering coco with 2gallons or 4gallons of the same nutrient solution just mean you'll have more run off? more nutrients don't get stuck in the coco?

K,
I think the coco guys worked this out over time. Trial and error. I'm not talking RUI...I mean coco growers everywhere. Ten years ago seems like people were shooting for 10% runoff.

The idea is that each watering becomes a little mini flush. I suppose you could water more...but it would be a waste of nutes. The coco will hold a specific amount...but beyond that it just runs through.

To add to the confusion...coco comes in different grinds. Really fine pithy coco can be overwatered so you have to let it dry a bit.

Please understand that people use and misuse coco in many ways. But from my reading and understanding...that way works best.
JD

just a note from experience: if your plants are lacking magnesium this should be evident from looking at middle to bottom leaves of the plant, thats where you will see this deficiency first, not at the top leaves near the buds
secondly, if your plants actually need magnesium then give them magnesium only, not calmag - i learned this the hard way, good luck!

Thanks Yosim. In this particular case it seemed like a Manganese deficiency on the excess/deficiency chart I have, not Magnesium. But that's good info either way. If anything this whole experience has left me wondering if I should switch over to DWC instead of Coco for my second grow.

I am also leading towards Folux or HLG quantum boards for my light upgrades, I hear great things about them on here, however I am ever skeptical.