1st autos @18 days, trimming q/advice

Hi all, thanks so much in advance. Below are the grow specs for the ticket and pics of my 18 day olds. I think all is well generally, but Im not sure what to trim or do at this point to stay on the right track. There’s undergrowth I haven’t had with photos. I don’t want to stress them unnecessarily, so I figured I’d ask first before cutting anything at 18 days. Just like a dude, right? :sweat_smile: I thought I saw something by @Aussie_autos on this, but couldn’t find it. Thanks again for your wisdom folks!!

• Strain: ILGM Autos; Bruce Banner and Runtz

• Method: Soil - FFOF with a HF center for the seedling

• Vessels: 5 gal. fabric, planted directly

• PH of Water, Solution, runoff: 7.7ph tap, Fox Farm Ph down to 6.5; Advance Nutrients’ Rhino Skin for silica.

• PPM/TDS or EC: Haven’t started testing runoff yet, watering 500ml every other day

• Indoor - 2’ x 4’ x 7’ tent

• Lighting system: Kind X420 at 75%; 16” from canopy; PPFD ~630; DLI -45; 20/4 cycle

• Temps; 87-90 day; 78-80 night.

• Humidity; Trying to keep it between 70-75%. Following VPD values mostly successfully.

• Ventilation system; The tent is in a utility shed that is lightly insulated and has a portable heat/ac unit. Inside the tent is a carbon filter with exhaust fan (off) and two small fans to circulate.

• AC, Humidifier, De-humidifier: Humidifier sadly has no auto-shutoff so it’s a pain to manage.

• Co2; No

• Age: 1/10/23 - 18 days

Bruce Banner:


Tent: BB on L, Runtz on R


I like to do as little trimming as possible. Maybe cut the “middle finger” off where it covers the future bud sites.(Like the one you are lifting up in the second pic) Just that center leaflet though at this point. The plant needs all the green it can make at first. Trim later if it gets too dense and good airflow is blocked.


I’d just leave them alone until you first start noticing pistils, then I’d clean up the bottom growth, and FIM it. Some people don’t top, or fim an auto, but I do. I like to keep the canopy as even as possible. My last GG auto.


I would letem grow. Later take off the bs stuff that tries to grow around stem. They will stretch up if lower junk gone. Auto have a finite number of fans. Take too many and yield will suffer. Just my thoughts.


Lower your light intensity at plant some and maybe lower lights on hours too. Your plants showing all the undergrowth because intensity is keeping vertical growth slow.

I would try to get lights on temp closer to 80f, and get a little drop if possible in lights out temp from there. Then watch vpd.


Good points. My first grow I had uber tight node spacing to the point of making it difficult to LST. Second grow I raised the light and backed off intensity. Got a lot better spacing and more vertical growth. I’m with you on the temps too. I’d want to drop each number by 10° or a little more.


I would do as stated above about light intensity and going to 18/6. Autos grow much healthier on 18/6. I always top my autos on day 21


I wouldn’t trim them yet i would let them get taller first you dont want to stunt the growth of it


Looking good Growmie. Sweet light and I run 1 as well. I would suggest dialing the light back to 25 on the DLI to promote some node spacing. 45 is max for me during flower. As far as defoliation I treat autos the same as photo periods just a little more selective on what I remove. I trim the lower 3rd up moving into flower and at day 21 and 42 of flower :love_you_gesture:

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@OGIncognito since it is a dual spectrum light would / or can the red be increased to promote more vertical growth in addition to raising it up?
@SandyC It must fill up the 2x4 very nicely. I have a previous generation K3 XL600

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Good point on the red and vertical growth/stretch . I can dial the intensity and IR up or down after that it’s a height adjustment if that’s what you were asking :love_you_gesture:

Yup, @beardless it’s basically the same size as the tent frame. The PPFD is pretty consistent across the entire space. The dual channels are nice too. I didn’t think the reds were added until flower though.

Thanks everyone, your advice leads to results!!

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I also run 18/6, I don’t top them I just tie them down these are like 8 or so they vary. But I had a smaller light sf1000 and got them back on the sc2000 so double the power. But I keep the light at about 18 away but once I got my other light back working they just went berserk.


I just got your question…early wake and bake :joy::joy:. That’s an great question on increasing the red on the IR and might have to give that a shot next time. I’m stuck at 50% full spectrum and 25% IR with the RG at 8” from the light :love_you_gesture:


I haven’t bought the ir……yet but big improvements on structure ? Don’t alot if the hlg have them already ?

You can increase your yield plus the canopy work is easier if you top or fim. I have no luck with fimming though :love_you_gesture:

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I just don’t like to cut autos. A lot of people do to get giant buds. I’m not that guy. I think a bigo bud has a better chance of getting mold?


Gotcha, different strokes for different folks. Mold is related to high RH and lack of air circulation though :love_you_gesture:


Yep yep. Air is key. Do you use those co2 bags?

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Yes that is true. However part of the reason for that is to prevent excessive vertical growth. Blue promotes more compact and denser growth.
This is a good video from Dr Bruce Bugbee that explains light spectrum and plant physiology

Another is by Professor DeBacco / DeBacco University