URGENT. Need advice with my 3 week old grow.

These two plants are of the type Big Bang and/or CBD Shark. They are 3 weeks old. i mixed the seeds by accident, so it is 50-50 on both plants. All feminized seeds.


The seedling is a 1 week old big bang. All ages are from seed, not germination. As you may notice, the larger plants both have an area of brownish leaves, which was caused by too few nutrients in the soil, a problem which i did not expect, as i prior to that killed 1 plant of nutrient burn. I feel i have a pretty good grip on the concept now, so dont take me for a fool.
What i want to know is, can it pay of to make a scrog from these plants, and how should i do it? It was my initial plan, but right now they make 4 new branches every time, and i dont even fim or prune them.
They grow under a dualspectrum 250 watt light, and there is a 60 m^3/h computer fan moving air over the leaves. the temperature is 30 degrees-32 degrees celcius, and the moisture 40%. the leaves temperature is 29 degrees mesured by IR thermometer, and the co2 is swinging from 700-1500 over the course of the day. so far they have gotten 24/7 light. the nutrients i have used are GH nutrients. the lux (Not lumens!) is about 10.000-20.000, so pretty much all paremeters are perfect. i also have an airpump pumping air in the pots from the bottom.
All advice is accepted, but please base it on science, and not just your own opinion.
Scrog or no scrog?

Them plants are burned to much co2 nothing above 1300ppm how do u know the swing is 700 to 1500? And trim off the dead parts of the leaves or dead leaves.

looks like you burned them last week.

cannabiscultivation said:

looks like you burned them last week.

Click to expand...

+1 As my alter ego could very well be, Knute Burns Sadly, them leaves look toasty, to me too. Especially the tips. This surely looks like nute burn to me. Been there, done that, saved 2 out of 8 I had to flush the snot (or more accurately, the salts) outta them.

That the newer growth looks better. Leads me to believe you have the nute /CO2 issue(s) more under control now.

As also posted, this burn may be due to too much CO2? Dunno? I run @1200-1300ppm in a small box (per my 24 hr logger). I haven't seen anything similar. But as the poster wrote, maybe you have to run over 1500ppm to see this? Perhaps this happened in the recent past? Which may explain why new grow isn't displaying the burn too?

Good luck with this grow!

R2T

I burned them last week indeed

• cannabiscultivation
  
  
  

, but i assure you it isn't because of too many nutrients. i tried changing the temperature, moisture in air and soil and flow of air, but it was not untill i added nutrients they began growing again. I have trimmed the plants as you said

• gweddo6868
  [FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif], and the new sprouts now get a bit more light. i have borrowed a co2 meter from my gymnasium, which allowed me to take the tests. it is first beyond 3000 ppm that co2 levels become toxic to c3 plants, which is cannabis. What i really need is to know is if making this scrog would benefit the plant, or just stall it- it have grown 4 branches at each point instead of the 2, so the plant is a lot more bushier than anticipated.[/FONT]
  [FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]I nutrient burned them as seedlings as the indicator for phosphorus failed, and i first found out when 1 plant was [/FONT]beyond saving.[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif][/FONT]
  
  
  
  
  

Wow anything above 1500 is toxic them are some good plants to made it seriously.but shit happens just move on I'm glad to hear that u trimmed the dead no need for the plant to try and repair the damage when it needs to move on.i don't think u need to scrog but u should if u want to. But if u want I can teach a good tech that will work for what ur working with alot better than that.

I would love advice, i just installed a screen, and flipped the top though. they are growing incredible right now, 2-3 cm this night. they didn't get more than 1500 ppm, as i said, but as far as i know it is first at 3000 it is toxic?

Natural atmosphere is at 300ppm pending where u live. Anything between 1100 and 1300 would be ideal anything above 1500 is toxic.

Here are a good tricks first thing keep ur plant low as possible the lower the plant less the harder it is to feed not working against gravity. Next tie ur plants with string most places sell it for two bucks Walmart etc. tie just under the main bud on each branch draw it up to the main stalk also with these do some selective trimming off the top of ur plant of larger fan leaves a light meter will help with this they are like fifteen dollars and can get them anywhere pretty much. Do this and in sure all ur bud sites are getting maximum light all the way down the branch and with training ur plant u can angle branches pretty much wherever u want. Ur plant will then start to get to heavy and u will to use hooks that can go into the wall to support the plant . I forgot to mention use milk crates to rise ur plant towards the light to help keep it low if u do this it will increase ur yields by a lot I have used these tech for years and I get three at a min and four and a half at max ounces out of each plant usually around four is average dried. Hopefully this will help I know it will work better than a scrog my last grow I did five plants and got a pound and a quarter pound off from them.

Forgot to mention genetics are important to need a good seed base. Never work with endless clones only from a seeded mother plant and take one set of clones from her this will ensure best genetics for growing anything behind that ur going to be dealing weak genetics its to far from the original source.

I know this is old, but i thought you might want to see how it turned out

nice look very healthy now

thanks
I did my best, should i just terminate the big bang?