Possible phosphorus or mag deficiency?

Wussup guys some of my leaves are not looking good and i need some help. Did some research and im thinking it might me a phos or mag problem but what do i know. Heres the info on my setup and some pics of the leaves

FFOF soil
5 gal air pot
temp about 67
humidity about 50%
watering with 6.5 PH RO water
about 5 1/2 weeks into veg
just watered a couple days ago with 3 tsp/5gal of flora micro, gro, bloom
problem started about a week ago.








 

MrGhettoGrower

Well-Known Member
No mention of Grow Big so if you haven't feed no nutes I would go with 2 tsp of Grow Big
the 2tbs of Big Bloom of course I guess it needs it too I do however wonder if you really need Big Blooom
or if it is just a money maker for the company 5.5 weeks in veg is a long time in veg how tall is the plant looks big and how
big do you want it cause it looks like it is going to be a bigger plant good luck~
 
I'm using the flora series micro, grow, and bloom. At 3 weeks I fed 1/4 tsp/gal of the flora series nuits. Next feeding was the same thing and the feeding after that was stright Ro water ph to 6.5 after the Ro ceding I fed 3 tap/5gal whichwas the last time it got watered. I know 5.5 weeks is along time for get but i have plants that are at different ages so I'm waiting for my youngest plant to hit 4 weeks then I am going to flower which will be on Wednesday.
 

sensiblue

Member
Some of your leaves do look like they are suffering from a magnesium deficiency, have you tried some Epsom salts?

Your temperature is on the low side also.
 
No i haven't tried anything. I wanted to know if i was right about the mag or phos before i did any thing. I also hoped the hereto the other day. I try to keep it around 75. I will look up Epson salt and see what i can find. I'm guessing that's to up the mag?
 

Thehermaphroditemaker

Well-Known Member
Almost looks like nute burn to me, maybe a wild pH fluctuation. Did you fertilize recently? Also, yeah, phosphorus is more likely based on what I can tell and charts I've read. Although I thought it started at the lower leaves first. (The almost moldy leaf appearance at the tip in the one pic especially) CA is easy to identify, it looks like spotting all over the leaf, and MG the leaves' tips will start praying. I think Cal-mag is always a good additive either way, and it might help. (Esp in flowering.)
 
I will get some calmag tomorrow. could it be cuz im giving it to little nuits? i was going to feed it 1tsp/gal next watering.
 

Thehermaphroditemaker

Well-Known Member
When this happened was it the first time you fed w/ liquid nutes? I also recommend liquid karma, that stuff is awesome, and it goes a long way despite the price. But one thing for certain is you don't want to add more if it's a pH problem which I don't think it is if you're using RO. Your problem is frustrating b/c your plant looks awesome otherwise. It could very well be simply a micro nutrient deficiency such as manganese. I think this makes sense because the one pit fall of RO water is sometimes a lack of micro. You might wanna simply water your plants with some pH'd tap water for a week and see if it helps. OR make sure to use the cal-mag with your RO every watering at light doses to supplement.

http://www.420magazine.com/forums/problems-pests-disease-control/81275-cannabis-plant-pest-problem-solver-pictorial.html <- Scroll down to the phosph deficiency and manganese part of the article and lemme know what you think.
 
Thanks for taking the time to help me out with this problem, I really do appreciate it. In the pics above the plant was just watered a couple day before the pics were taken. And that was not the first time it was giving liquid nuits. First nuits feeding was at 3 weeks old and it got 1/4tsp/gal of micro, grow, bloom. Next watering it got the same mix of nuits and after that watering it got just stright ph ro water. Then next feeding it got 2tsp/5gal, then ph water then 3tsp/5gal, then the other day I watered again with Ro water. But I'm pretty sure it started before the last nuits feeding. Over all the plant lks good just mainly one area where the leaves are not looking so good. It is also starting on the bottom of the branches but it will be hard u guys to notice cuz the plant is being LST. And after looking at the pics from the link u posted it would have to say it looks more like a mag problem. I did buy some cal-mag yesterday too wo I will be using that soon. I was going to flower then today cuz the youngest plant is 4 asks old and almost all the other plants are at 5-6 weeks of veg. Would I wait till I have this under control before i flower?
 

Thehermaphroditemaker

Well-Known Member
Thanks for taking the time to help me out with this problem, I really do appreciate it. In the pics above the plant was just watered a couple day before the pics were taken. And that was not the first time it was giving liquid nuits. First nuits feeding was at 3 weeks old and it got 1/4tsp/gal of micro, grow, bloom. Next watering it got the same mix of nuits and after that watering it got just stright ph ro water. Then next feeding it got 2tsp/5gal, then ph water then 3tsp/5gal, then the other day I watered again with Ro water. But I'm pretty sure it started before the last nuits feeding. Over all the plant lks good just mainly one area where the leaves are not looking so good. It is also starting on the bottom of the branches but it will be hard u guys to notice cuz the plant is being LST. And after looking at the pics from the link u posted it would have to say it looks more like a mag problem. I did buy some cal-mag yesterday too wo I will be using that soon. I was going to flower then today cuz the youngest plant is 4 asks old and almost all the other plants are at 5-6 weeks of veg. Would I wait till I have this under control before i flower?

Sounds like a good idea to veg them a little longer to make sure the problem isn't persisting. I'm hoping the cal-mag works out for you, seems like the cure for most ailments people post anyway. Another thing you could do is re-pot them one more time into a 7gal or something - i think that along with the calmag should clear it up. (if you haven't already put them in their final pot, however big it is.)
 
So i should just feed with cal-mag and Ro water for a week right? Also should I just follow what the bottle says for dosage?
 

Thehermaphroditemaker

Well-Known Member
Well, tap water is usually 100-300ppm, do you have a ppm meter by chance? I'd try to get it around that with the cal-mag. Otherwise, I'd start with a tbsp a gallon or less and maybe foliar feed it first to give them an extra boost. Plants absorb through the leaves quicker too. I usually just put a cap full or less per gallon of water and it's helped resolve any minor problems along with a foliar spray. My 2 cents on application rates, but there may be a more definitive guide somewhere on the net on how to apply it. I hardly ever measure stuff exactly to be honest.

One think i'd do personally to be careful is to apply it only when you're fertilizing, every other watering I suppose. Don't want to overdo it. RO or not, if you're adding it to your nutrient regiment you should be golden.
 
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