Need help, short plants

[Benefaktor]

Hey guys, I have a problem. My plants grow very slow and are very short. The bigger one is Big Bud and started 19.12.2021 the second is Northern Light started 13.01.2022. Both from feminized seeds. I grow them in hempy buckets filled with coco( cleaned and prepared for use). I feed them 6 times a day with 6/9 Flora Micro and Flora Bloom mixed with RO water. Ph is 5.5 to 5.7 505 ppm, runoff is 570 ppm 6.2 pH. The light comes from chinesee Led lamp 2000W real consumption is 380W, temperature 23-25 Celcius. Where is the problem?

 

[amanda88]

another 380w light may well fix this?

 

[goingrey]

Based on the photos the light is very limited in its spectrum (just red). Possibly that is the reason.

 

[bigpeter]

A plant grown in coco needs to have a decent root system before it can take multiple feeds per day. If that was my setup, I'd stop watering for a while until the plants got a decent root system established and then start more frequent watering.

 

[Benefaktor]

The plants have fully developed roots, acording to the light I could change it but I have only HPS 400 I heard that it is good for bloom not for grow. I'll try.

 

[Creeperpark]

Mix the 400 HPS with the red LED and your plants will do much better. I've used HPS mixed with LEDs and had super results.

 

[Benefaktor]

I 'll try to mix HPS and LED but the led lamp has wide spectrum of light, photos are misleading, in fact the light is brighter.

 

[troutman]

I'm not sure about all the other variable you have going. But low humidity
below 60% will make for slow growing plants when in vegetative mode.

 

[Three Berries]

How far away is the light? Bring it up to make them stretch.

 

[Benefaktor]

The light was away from plants, I thought it makes plant stretched. Today I got the lamp lower about 30 cm above plants.

 

[44:86N]

Do you know the spectrum on that lamp? My veggie LED is all blue and white, and that one makes short inter nodes, also, when placed too close.

Vegging plants want a spectrum of 400nm to 500nm, or 5,500K to 6,500K. Your lamp light looks either too low or too high in those values... almost ultraviolet.

Maybe hit them with some extra phosphorus. That will get the stems stretching.

 

[goingrey]

The plants have fully developed roots, acording to the light I could change it but I have only HPS 400 I heard that it is good for bloom not for grow. I'll try.

HPS is fine for veg (grow). It's what most people used to use before LEDs got popular. Sure some people might have used an MH bulb or even fluorescent lights for veg. But most just went with the HPS for both veg and flowering.

 

[Lester Beans]

Raise your Ph to 6.1. 5.5 is too low and the plant shows.

 

[Benefaktor]

I have replaced led with HPS yesterday and wait for results. According pH 5,5 is perfect in coco, leafs do not show any bad symptoms, they are bright green without any spots. The plants look healthy, only stalks are short. Now I need some time to see if the light was the problem.

 

[Lester Beans]

No that's incorrect. 5.5 is too low for Coco and the leaves show it. If you know it all why ask? Best of luck to you.

 

[Benefaktor]

Lester where my leaves show bad pH? Am I blind? I am pretty sure that pH is correct, I always run 5,5 and it was good for my plants. Led lamp is the only new factor. Within the next few days it will be visible if the light was a problem. By the way, do you use coco?

 

[Lester Beans]

I have grown in every medium. The proper pH range for Coco is 5.9-6.1. hydroponics 5.8. soil 6.3-6.8. Show me one good coco grower who keeps pH that low.

I had to make the pic black and white to get rid of the led blurple color. The leaves have twist and are clawing upwards. Low pH is locking out some nutrients, stunting your plant.

I am just trying to help you, and the pH is the glaring problem.

 

[Benefaktor]

Lester thank you for your adviceI appreciate it but the leaves are twisted because of me, I did it accidentally. H3ad, Rezdog are growers who grow in coco using pH 5.5, their posts are sticky on Icmag https://www.icmag.com/forum/icmag-v...eeder-forums/reservoir-seeds/77264-the-recipe
https://www.icmag.com/forum/marijuana-growing/growing-in-coco-coir/50670-h3ad-goes-coco
It is not my first grow in coco, I always try to keep pH 5.5 to max 5.7 and had good results. Cheers.

 

[Lester Beans]

Ok glad you got it figured out. Let us know how they are doing.

 

[Creeperpark]

I have replaced led with HPS yesterday and wait for results. According pH 5,5 is perfect in coco, leafs do not show any bad symptoms, they are bright green without any spots. The plants look healthy, only stalks are short. Now I need some time to see if the light was the problem.

If you keep the red light too the plants will adjust faster. Use them both if you can for the fastest fix.