My first grow

[420RPM]

Hi folks!

This is what my three girls look like 13 days after germination.
Growtent 90x90x178 cm, ventilation with carbon filter from Secret Jardin

300W Lumatek LED is 100 cm from plants running at 50%.
Biobizz all mix in 11 liters Airpots.
Northern lights auto from Nirvana seeds
Temperature is about 24 C.
I'am using a small humidifier that keeps everything about 55-60%
I also run a monkey fan on the same timer as the light 18/6

When can I increase light to 100% and start using light fertilization?
As a beginner, I am grateful for any advice.
​

 

[Gingerbeard]

100% light at manufacturers recommendations.
I'll say it again: I have seen a number of people in this forum have nutrient issues with Biobizz. It is a hot soil. You seem to have done well with it in that you have not posted about nutrient issues and do not seem to be showing any. Good on you for that!
That being said, you might very well not need to add veg nutes. That's the deal with premixed soils. Unless they say otherwise, they contain nutrients for veg growth, but not so much for flowering. That is fine looking dope for a 13-day old auto. 13 days is not enough to flush enough of the veg nutes to require more than single-digit percent recommended dose of nutrients.
Whatever you choose, keep a good eye out for nutrient burn. It can be difficult to come back from nutrient burn if you can't stop the plant from taking up nutes which would be the case in premixed soil.

 

[Bluey]

Growing autos with that light in that size tent on an 18/6 schedule probably will never need 100% light if the light is kept the correct distance from the plants. This is the sweet spot that gives the most even light spread.

You'll be at maximum light around half way into flower.

Best to download an app for your phone and use the DLI measurement. A Max of around 40 to 45 should be about right but watch for light burn. I get nute issues, deficiencies, typically before light burn becomes an issue with my setup.

Being your first grow a conservative approach is often best with nute levels and light. Focus on maintaining the correct environment. The manufacturers recommended nute levels are often too high so if you are measuring EC stay around half to a nax of ¾ recommended levels at max.

With that soil you will probably only need bloom nutes after flowers appear, which is what I think Ginge is recommending.

 

[Gingerbeard]

B-diddy. Why half power? If the light actually outputs 300 watts, that tent is getting 33.3 watts per square foot. Why would you recommend less?
I'm American. Sorry about converting the more pragmatic metric to imperial. Did you know time is metric? We imperialists did to time what Christians did to Paganism by making people think it was our idea.

 

[Bluey]

Being an auto it will get its DLI over an 18hr period.
Running the light at 65/75/80% will give it 40 odd DLI if it's in the sweet spot and less heat to deal with and the light and driver will last a bit longer and less electricity too.

If it were a photoperiod it would probably need closer to 100%

If time is metric then space must be too and they are neither. Just ask Albert

 

[Gingerbeard]

I ain't arguing with you because I don't know what DLI is. It just seems counterproductive like giving less nutes. Y'all do it, but I'm sticking to my nugs.
Albert's dead... ran out of time.

 

[Bluey]

DLI is the measure of how much light a plant gets over a day. Plants can only process so much light in a day period. If you give them more than they can handle in a day they shut down, their branches and leaves droop and it appears they have been overwatered or just go to sleep...they look like how they look in the middle of their dark spell. This is the Daily Light Integral..

If you look up a graph on DLI you will see graphs for different light schedules and intensity measured in PPFD. As an example typically photoperiods in flower that can take 1000PPFD over 12 hours of light equate to 666PPFD over 18 hours of light for an auto giving them the same amount of light over the day, so the same DLI. Big variations in DLI comes down to strain. Sativas can handle much more than indicas in my experience.

Graph below which shows the relationship.

 

[Bluey]

Graph from this website. Makes for a good read about DLI https://albopepper.com/dli-ppfd-calculator.php

 

[Gingerbeard]

Read? Booty, my friend, it has been raining all day. I have been doing those rainy-day dabs I have been saving up and ripping my grower's stash from the Razzpergers. I am far too forked up to read for knowledge. But that graph sure is pretty! Colorful and scientificul.
Maybe I'm just lucky. I do autos balls out light and nutes and don't give a hoot about temperature and humidity because I can't do anything more than adjust my fans.

 

[420RPM]

Hi and thanks for input.
33 days since sprout and i have a new problem..Brown spots, Could it be calcium deficiency?
pH of my tap water is 7.2 and the runoff from pot is 8.
Should I lower to pH 6 and buy some Cal-mag?
Have not added any nute yet.

 

[Bluey]

Adjust your pH to suit your medium and stage of growth. Its too high.

Being in soil and in veg the recommended inputs are 6.2 to 6.5 and transition to flower 6.5 to 6.8.

Calmag not often needed in soil grows, maybe it's running low on nutes in the soil so you could start veg or bloom nuted at a low dose if needed. pH first though.

 

[Gingerbeard]

From the Biobizz website:
"In general, when using organic nutrients, pH adjusting is not necessary. This is because the Biobizz products tend to lower the pH naturally until it comes to the optimal range of 6.2-6.3.
However, in some cases the base pH of the tap water can be too high or the grower chooses to use RO water with a very low pH. In those cases, you can use Bio·Up and Bio·Down to regulate the pH of the mix before watering your plants."
Also according to their feeding schedule, their veg nutrient can be used after the first week. However, I personally would not use veg nutrients in premix soil, growing autos. Fertilizer makers do not take autoflowering marijuana into consideration when they write their schedules. Really, most of the feeding instructions out there are not for autos.
Other websites are varied on the use of calmag with Biobizz but say to use it if your plants tell you they need it. I didn't read anyone who said just don't use calmag.
​The shown damage is old. Nothing you can do except worry. This looks like a case of something happened but is no longer happening. All things considered, get some calmag and follow the manufacturers recs.

 

[Radeon]

First 2 pics look like over watered. 3rd pic, the plant in the background looks good. Let the 2 droopers dry out for about 3-4 days and see if they perk up. Its isolated so I wouldn't panic. Also watch if it stops or continues. Usually when you just have a couple fans that do that its a root problem. Thats just from my experience. Could be wrong....

 

[420RPM]

Hi
Thanks for all the good advice. It has now been 52 days since germination. I give them water pH 6.2 every three days with Biomix Bio-Bloom. 50% of the recommended dose. Also give Calmag 1ml/liter.
Removed dead leaves and some light lollipopping.
Daytime about 24 C and 54%
300W led at 75%

So gentlemen!
What do you think? Am I doing something stupid?
Are the leaves really supposed to be this yellow?
Btw, the green one on the right is 10 days younger than its sisters.​

 

[Bluey]

You should be dosing PK as a suppliment at that stage. Not so much if any calmag.

When you water them are you making sure you are not getting runoff? In soil grows if you are getting runoff then you've just washed all the goodies out.

pH of inputs should be 6.5 to 6.8 now

 

[420RPM]

Thanks Bluey!

The girls were watered yesterday with half the recommended dose of veg and flower nutrition. No calmag. The water was adjusted to pH 6.5 Before and after the nutrition was added.
Watered slowly without runoff.
Light at 75%
54% and 24 C
It feels like i'm getting close to harvest (63 days).
Should i flush at least a week before harvest?

/420RPM​

 

[Bluey]

No need to flush.

Reduce light and nutes a little last two weeks, watch for less uptake of water, it will drop off fairly quickly then you're on the home stretch re your last couple of weeks typically, trichomes should be mostly milky/cloudy when that happens