Shit spots! Potassium/Phosphorus Deficiency?

Weouthere

Weouthere

Well-Known Member
Hey y’all! This grow has been going great up until this point. I’ve noticed some shit spots or like bruises on the leaves, as well as some rust spots (like calcium deficiency) on my ATF plant.
4x4 Tent
480w Meijiu board (3500k)
Ffof/happy frog (50/50) with 3 parts perlite, 1 part EWC.
Water with tap water left out- add Humboldts Killer Tea every watering. It’s also gotten a couple doses of Roots Organics “Extreme Serene” And I’ve started using Fox farms big bloom at half strength the last 2 waterings (with a watering of just tea in between).
pH is 6.5-6.7 for water. Need to test soil at next watering.
Im thinking it’s a potassium or nitrogen deficiency but I’m not sure as I’ve never seen them in person. Gwe has some good info but I just wanna make sure before I give it more and fuck it up worse.

edit: now I’m thinking phosphorus deficiency after more research. Any ideas?
 

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Weouthere

Weouthere

Well-Known Member
polishpollack said:
Did you know that those soils have nutrients in them already? Most common mistake growers make - giving too much fertilizer.
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Yeah obviously lol.
I ran just ffof last time and ended up needing nutrients in late flower, but didn’t have any/didn’t want to risk ruining my crop. I’ve learned some more and I wanted to try this soil mix. It’s worked pretty well so far. I’ve needed to water with some Epsom salts but that’s the only deficiency that popped up.

The tea feeds the soil, the big bloom is just an extra boost in p/k since that’s what I needed on my last run. Serene because it’s a soil wetting/rooting agent.

After doing more looking it looks like it’s a phosphorus deficiency. Any thoughts on that?
 
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Federucci

Well-Known Member
The first thing I would try is watering your plants with plain water at closer to 6.0pH, maybe 6.2ish, than 6.5-6.7 and observe the results. If it does not get better, then a 6.2ish pH water with a small dose of "multivitamins" with manganese and all the regulars will probably work, but I get the feeling this is an availability issue as you have watered with 6.7 pH water and that's a bit higher than optimal from what I have experienced. Someone with far more knowledge than myself should also chime in.
 
Weouthere

Weouthere

Well-Known Member
Federucci said:
The first thing I would try is watering your plants with plain water at closer to 6.0pH, maybe 6.2ish, than 6.5-6.7 and observe the results. If it does not get better, then a 6.2ish pH water with a small dose of "multivitamins" with manganese and all the regulars will probably work, but I get the feeling this is an availability issue as you have watered with 6.7 pH water and that's a bit higher than optimal from what I have experienced. Someone with far more knowledge than myself should also chime in.
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The tea I’m using is basically that multivitamin! Awesome.. I’ll just pH my water down. If it doesn’t fix it should I go ahead and add some pk booster? I have one I haven’t open.. it’s Supernatural Budblaster 0-42-39 or something like that.
 
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Federucci

Well-Known Member
I love some nice tea too man! I'm curious how it goes over the next few days. I think there may be some nitrogen stuff going on rather than the other two, but isn't it kinda fun and rewarding to diagnose this stuff? Subbed to know how it goes buddy.
 
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Weouthere

Weouthere

Well-Known Member
Hey man just wondering.. i had a bottle of 1-4-5 botanicare pure bloom.. I just poured it down the drain as it’s like 4ish years old and nasty smelling and there’s tons of precipitates in it.
Anything like that you could recommend? The big bloom doesn’t have nitro in it. I’m about to look into some GH stuff, never used it before though.
 
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Federucci

Well-Known Member
What I personally use is Rainbow Mix Grow and Bloom, but it's pretty expensive, so I might want to use something else in the future. Outstanding stuff though, especially for people who like to feed plants more than they should, lol. I do a foliar feed of kelp meal because it has some nitrogen in it too and the bacteria seem to like it, you can get some pretty cheap. Every month or so I give a dose of "Sea 90", it's pretty much every known micro and stuff known to man, but you have to be judicious in use. Check out "Master Mark's program". I use it for ghost peppers with great success.

Edit:

https://www.growweedeasy.com/cannabis-plant-problems/manganese-deficiency

This says to flush with pH correct water mixed with a balanced regular dose of nutrients to get out salts/iron as that can prevent uptakes. I bet that's the ticket.
 
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Weouthere

Weouthere

Well-Known Member
Federucci said:
What I personally use is Rainbow Mix Grow and Bloom, but it's pretty expensive, so I might want to use something else in the future. Outstanding stuff though, especially for people who like to feed plants more than they should, lol. I do a foliar feed of kelp meal because it has some nitrogen in it too and the bacteria seem to like it, you can get some pretty cheap. Every month or so I give a dose of "Sea 90", it's pretty much every known micro and stuff known to man, but you have to be judicious in use. Check out "Master Mark's program". I use it for ghost peppers with great success.

Edit:

https://www.growweedeasy.com/cannabis-plant-problems/manganese-deficiency

This says to flush with pH correct water mixed with a balanced regular dose of nutrients to get out salts/iron as that can prevent uptakes. I bet that's the ticket.
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Dude you’re the best haha. Thank you so much. I actually just got back from the store. I picked up some Jacks Classic Bloom. 10-30-20. It’s got all the micros as well.
Going to pH my water to about 6 then hit em with the Jacks. Just did a soil test (cheap kind) and it read almost pH 7.
 
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Federucci

Well-Known Member
Awesome! I have a feeling that it'll work just fine. I would definitely pH the solution after adding the fertilizer, might take it lower than you think, I know I messed up with that before lol.
 
Weouthere

Weouthere

Well-Known Member
Federucci said:
Awesome! I have a feeling that it'll work just fine. I would definitely pH the solution after adding the fertilizer, might take it lower than you think, I know I messed up with that before lol.
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Just finished watering! They got 1 gallon of water each (I need to up this, theyre in 5gal pots) pHed to 6.0.
Added a dose (1/4 tsp) of the Jacks Classic Bloom (10-30-20) which didn’t change the pH at all surprisingly.. I was skeptical just as you are about it changing it drastically.
I also tested the runoff (what little there was) And it was 6.2.
I’ll update how they look in the next few days but I’m confident this made a big difference :)
 
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Federucci

Well-Known Member
Very excellent. I have found 6 to be a pretty safe number, if my tester is off by as much as -+ .5 for whatever reason, it's still safe enough.
 
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Federucci

Well-Known Member
I'm willing to bet that they will respond nicely by tonight. They could very well be a little short on mg judging by the last photo too, although it appears that the yellowish vein and more greenish leaf on some leaves and some general yellowing of others is a combo deficiency of Mn and N, but I am NOT an expert. The 6.0 pH should make more nutrients available buddy. I just had a magnesium deficiency where the chlorosis made yellow leaves with dark green veins, remedied with 6.0pH water and cal mag and things are looking ok. I would be willing to bet that the vast majority of issues are caused by pH affecting nutrient availability that are compounded with overwatering, at least that's how it happened to me lol.
 
Weouthere

Weouthere

Well-Known Member
Federucci said:
I'm willing to bet that they will respond nicely by tonight. They could very well be a little short on mg judging by the last photo too, although it appears that the yellowish vein and more greenish leaf on some leaves and some general yellowing of others is a combo deficiency of Mn and N, but I am NOT an expert. The 6.0 pH should make more nutrients available buddy. I just had a magnesium deficiency where the chlorosis made yellow leaves with dark green veins, remedied with 6.0pH water and cal mag and things are looking ok. I would be willing to bet that the vast majority of issues are caused by pH affecting nutrient availability that are compounded with overwatering, at least that's how it happened to me lol.
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So I just checked the plants! When I watered last night it was an hour before lights off so I couldn’t check them till today.
It seems that the pH and the Jacks helped SLOW the deficiency. It had advanced quickly and today it had still advanced, just not as quickly as the last couple days. The pic is of a leaf that was mostly healthy yesterday but today looks like this.
Im starting to lean more towards calmag now. Next watering they’ll get the Jacks and calmag. Hopefully that will clear it up.

Of the 4 plants I have flowering now, this one that has the problem is my girlfriends, so I really want it to be healthy. She’s so sweet and it’s hurting her heart that her plant isn't doing great.

That also makes me think it’s just a little different feeder, as up till now I’ve been giving all 4 plants the same water/feed, and they’re in the same medium.
gonna do some more research on ATF specifically
 

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Weouthere

Weouthere

Well-Known Member
Question- can I water with calmag today after I watered last night?
Will that flush what I put in yesterday or give the plant symptoms of overwatering?
 
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Federucci

Well-Known Member
A lot of the time the damage has already been done but you can rectify that on the new growth, if I were you, I would hold off on the watering with calmag, or watering period until it needs another watering, possibly a day or two until the top inch or so of soil gets dry, and then flush again with the magical cal mag at around 6.0 pH. You can also do a foliar feed of the calmag today and observe the results too. The fact that it has slowed tells us that you're on the right track man!

One question I have is do you know how many lux or PAR is shining down on these girls? I just realized that I was bombarding the plants a while ago and due to the light stress they showed yellowing in some higher areas on the exposed leaves with yellowish kinda burnt ends going into a tip, and it might be my imagination, but I took another look at your plants and they looked similar to mine at that stage last year, some of the taller leaves were a bit yellow with those tips, but some of the lower ones also have those tips, and it's hard to tell for sure in your first post photos, but the centermost plants appear a little yellower than the lower leaves and those around the edges.
 
Weouthere

Weouthere

Well-Known Member
Federucci said:
A lot of the time the damage has already been done but you can rectify that on the new growth, if I were you, I would hold off on the watering with calmag, or watering period until it needs another watering, possibly a day or two until the top inch or so of soil gets dry, and then flush again with the magical cal mag at around 6.0 pH. You can also do a foliar feed of the calmag today and observe the results too. The fact that it has slowed tells us that you're on the right track man!

One question I have is do you know how many lux or PAR is shining down on these girls? I just realized that I was bombarding the plants a while ago and due to the light stress they showed yellowing in some higher areas on the exposed leaves with yellowish kinda burnt ends going into a tip, and it might be my imagination, but I took another look at your plants and they looked similar to mine at that stage last year, some of the taller leaves were a bit yellow with those tips, but some of the lower ones also have those tips, and it's hard to tell for sure in your first post photos, but the centermost plants appear a little yellower than the lower leaves and those around the edges.
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Sweet! I’ll hold off on the calmag for now. The progression has slowed so I feel a lot better and have no problem waiting to water.
I don’t necessarily want to foliar feed as I’m into week 2-3 of flower.

I have wondered about the light.. I might raise it again as the plants have grown quite a bit since I raised it like 2 weeks ago.
It’s a 480w Meijiu board (alibaba light) that I have turned all the way up, sitting about 20” from the canopy
I’ll go raise the light a bit a see what happens.
Edit: raised the lights. I measured them before and they were actually closer to 15”-17”. Raised em to 24”-25”. I’ll check back in some hours and see how they responded.
 
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