Plants stopped growing


#1

hi
it s my 26th day of growth and my plants have stopped growing ever since i transplanted them in 13lt pots,their height is 6-8 inches.one week ago the 2 bottom sets of leaves on all of my plants (10)turned yellow and died in 3 days,when i removed them i noticed that the stems were white.plants have stopped growing ever since.i had an MH 400 on before the transplant and turned on 2x 300w leds after.
i hope you can see something from the pics these are the most clear pics i could take





stems are half green half white

ILGM Support Ticket:

What is the strain and type(master kush)

Indoor
Size of space (max height 3m length 3m 4m width)

Soil

pH? i water with 6.1

Type and strength of nutrients used? marijuana booster (just once until now,i have watered plants with nutrients one week ago but still have not dried

Temperature? Day 23-24 C night temp 18C Root zone temps?can t measure that,don t have the right tool

Humidity %? Day55-65 Night 75-80

Light system/ started with 250w MH then changed to 400w MH and now i am using 2x300 leds
also have a 600w hps to use for flowering

Ventilation system? YES AC-YES Humidifier, De-humidifier?NO
there is enough oxygen getting into the tent daily

26th day of Vegetative Growth


#2

Well then. I would have to ask. When did the issue start? When I re-potted and placed under LEDs

PH for soil should be adjusted to: 6.5-7.0


#3

yes the problem started 2 or 3 days after the final transplanting and my plants are still like that 10 days later.they don t grow!
what should i do to fix this?change lights again?do smt else?
i would appreciate it if somebody would identify the problem and suggest a solution for me
thank you!


#4

I would wait for their esponse; however, it ses like, if they are in soil, a pH of 6.1 is t low. You want ~6.5.

Have you tried returning them to the original lighting, in order to see if the LED is part of the problem?


#5

I cannot see asn issue becuase your pictures are so RED; You cannot make out much mor ethan what appear to be healthy plants.

As mentioned; Your PH was way off. When you transplant; It takes 10-14 days to see new growth because hte roots have to develop. I do think it is odd that all your issues started when you switched lighting systems. Take the hint :wink:


#6

thank you very much,this is an answer that makes sense,actually they are ok now growing again normally after 8-10 days that stayed still.
i changed into the original MH lighting again and raised ph to 6.7 but i have a question about that.
i am a rookie grower and i just did what the watering schedule that mac g gave me was saying,so i was a little surprised when you told me that 6.1 ph is low…it says in the watering schedule that we should use 6.0 ph throughout the whole growth period so i wonder that maybe there is something written wrong?i don t know anyway problem solved thanks again Latewood and le Stat for the immediate response and valuable info.
i am also wondering how many plants can i place under a 400 W MH and how many under a 600w hps which i will use for flowering later so i can have a satisfactory yield in weight?
only have 1 and 1 now but i am sure i am going to need more for 10 plants so i am asking you :smiley:


#7

I don’t necessarily think the 6.1 pH nor the LED lights were the cause of your problems. 6.5 is the pH to aim for in soil, but normally 6.0-7.0 is not a lot to worry about in a good soil. LEDs can be just as intense as HIDs for plants and the light being too close can be a problem even if it doesn’t feel too hot like it would with a HID.

All plants need to go through a “hardening off” when transitioned to stronger lights. This means slowly increasing the intensity of the light to get them used to it. It is the same when bringing plants from weak indoor lights to the outdoors intense sun.

The fact that you transplanted them is likely what slowed the growth, they need to establish their new root zone before you’d notice a lot of new growth above ground.

The leaves in the picture look a little “bloated”, as if from over watering, this can be a big problem for a lot of people. Be sure to let the soil nearly totally dry between watering or feeding. Then when you do water, soak to saturation once, and again let nearly dry totally before watering again. Determine this by the feeling of the plant and the containers weight, don’t water again until by weight it feels almost totally dried out.

Just some more info and things to think about.

~MacG


What soil mix to use when using strong liquid fertilizer?
#8

Well, I was going to say that MacG was talking about a solution and PH for Hydro. I don’t know what he is talking about now. Best to keep your PH close to normal. If you allow your PH to get to far outside the known PH of 6.5 -7.0 for soil; You are asking for issues to develop. It is not worth it.

And; I do not think the LED comment was meant for me, but I want to clarify; I never said the lED lamps were an issue.


#9

Actually, you kind of did.

Of course this could be equally interpreted that more intense light in general could be part of the problem, and I don’t think there needs to be a disagreement or argument about it, lol. I just wanted to clarify it might not be the LEDs themselves, per se.

However, I do disagree and we have disagreed on this in the past as well but it’s not a huge deal as I do say and so do others, that in soil anywhere from 6.0-7.0 is usually ok.

Nebula Haze:

What’s the Right pH?

Soil - 6.0-7.0 pH

Hydro/Soilless/Coco - 5.5-6.5 pH

http://www.growweedeasy.com/ph

Even Robert says: “Marijuana grows best in water or soil with a pH level between 6.0-6.5 (slightly acidic).”

Or even Cannaversity:

“The cannabis plant thrives in slightly acidic pH levels. Soil growers should aim for a pH range of 6 - 6.7 , Where as Hydro growers should go slightly lower which helps prevent pythium and other forms of root rot keeping that in mind the ideal range for a hydro grower is between 5.6 - 6.2 the only exception to this in a hydro ponic medium is in the case of coco where the ph should be closer to the range used in soil grows however not allowed to fluctuate past 6.5”

http://cannaversity.com/cannaversity/article.php?id=039

https://cannabis.community.forums.ozstoners.com/cannaversity/uploads/pHrange.jpg

~MacG


#10

Sorry. I did say that and stand by it. There was no issue until the change. When there are issues; The 1st thing we must consider are; What changes did you make? I meant I have nothing against anyone using LEDs.

The graph above is about exactly how I see it. 5.5-6.1, and 6.3-6.8 works for me too! Best graph for the site impaired I have seen. Thanks for sharing that one.


#11

Woo Hoo! I love it when we agree on the bigger picture, lol.


#12

i hope you 2 are done fighting because i have 2 more questions :stuck_out_tongue:
it s my 3d attempt for growing and the last 2 times my plants were growing a lot faster,i mean even before i start having these problems on the 4th week they should be a lot taller.
i keep notes and the first time i grew,plants were 1m tall before the end of the 4th week.
my tallest plant is 35cm and the rest are 18-25cm and it really makes me wonder because the first 2 times i tried to grow i could not control the temperature inside the tent but still they grew fast and without problems(problems started in flowering period where i was completely torturing the plants by using nutrients on every watering and temps were really high sometimes maybe even more than 35 C !!
now i keep everything in balance since day 1 but the results are disappointing.35 days of growth until today and normally i would turn to flowering period after this week but i think it will take a lot more weeks.they don t grow more than 2 cm per day and this is not for all plants.i have a specific one which had issues from the beginning and it even got burned slightly on the leaves when i used marijuana booster for the first time in it so i got scared and left it alone,it s not dying but it is not growing either and i am thinking that maybe i should remove it.
why do i have this very slow growth now that i have done everything i should do since the beginning?
even if we don t count the 8 days that i had these issues it s still 4 weeks of growth and only 18-25cm in most plants
and my 2nd question is this.i keep all 10 plants under a single 400w mh lamp at this moment.i am thinking that i should use maybe 3 600w hps lamps when i turn to flower.is this right or more intense light might damage them?or should i do smt else?
and how much distance should i keep from one plant to another in flowering?
thank you


#13

We really need the nutrient concentration, the EC or TDS or PPM, parts per million concentration of your nutrients and what is building up in your soil, as well as the pH in the root zone, in the soil. Testing the TDS and pH of the extra water that runs out the bottom, the “run-off” would give us a general idea of what is going on in the soil.

Also, I still think over-watering might be part of the problem.

More intense light is almost always better.

Have you done your calculations for your area’s required watts? I’m not sure the conversion to metric, but the industry standard is about 50 watts per square foot (about 30cm x 30cm ) of canopy for flowering, you can get away with a lot less for veg.

10 plants in that size area? You obviously want them about equally spaced in the floor space. Also it could depend on how big you want the plants to get, bigger plants means less plants per area.

~MacG


#14

Also, get that pH up to 6.5, to help rule that out as the problem.

~MacG


#15

so if i understand correctly the run off is the water that runs out of the bottom of the pot and this is exactly what you want me to test right?
i have a ph meter of course and a tds meter as well so i will test what you asked next time i water my plants and let you know about the results
you said that ovrwatering might be a part of the problem,i am 100% sure that the only time i have overwatered was when i transplanted for the 3d and last time,i had watered the plants in the medium pots 2 days before i transpant them and then i watered them again after the transplanting so that soil would be all wet and i think i overdid it.their size at that time certainly did not demand that much water.
i didn t quite understand what you said about the lights,you see my english are not as good as they might seem.so please just give me a number…i have a 16 square feet room for flowering how many 600w hps would you suggest for 10 plants equally spaced in that area ?
thanks


#16

10 posts were merged into an existing topic: Any idea on Strain or Variety of this plant


#17

If water is sitting and staying too wet at the bottom of the container, this can also cause symptoms of over-watering.

You need 50 watts per 30 x 30 cm, this is roughly equivalent to a square foot or 12 inches x 12 inches.

~MacG


#18

you guys are hilarious you keep me laughing wish I had some smoke so I could be laughing harder have a couple of more months for that I’m not buying nothing Nomo LOL