Trouble with first grow

I'm having trouble with my first grow. 2 White Widow Autos, growing in soil Royal Gold Mendo Mix, 3x3 tent, 300w light, 80 temp, 61%humidity. Plants have been sprouting for 24 days and are not growing, bottom leaves are yellowing. I'm not using nutrients. Any ideas of what i can do to try to save these.
Thanks

I hate to say it but if that plant is 24 days old you should just start over .

Unga Bunga said:

I hate to say it but if that plant is 24 days old you should just start over .

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Agree. For an auto it's bad to be that far behind.

OP,

Mendo Mix is heavily amended and is for established plants. You don't want to put seedlings in it.

Also, you can't say 300w light and not mention the dim setting and hanging height. How often were you watering it?

Light is 48" at 50%, watering every 2 days. Mendo Mix is what the shop recommended. I will start again,
Thanks for your quick replies.

suba.nakni said:

Light is 48" at 50%, watering every 2 days. Mendo Mix is what the shop recommended. I will start again,
Thanks for your quick replies.

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U might be burning it with that 50% but if that's 24 days old I'd start over
I'm new to this. This is my first grow and my plant was like that for ab 15 days but I upped my watering and I had shitty light so I got new ones and they bounced right back and there doing great now
But looks like u might have underwatered and put ur light to high for that to stunt or sum idk bur I had the same problem almost
How much water u give it?

Start over in soil with no added nutrients and be careful how much you water. That soil also looks like it's full of leaf matter, etc.. not really ideal to plant seeds in. Never plant autoflowers directly in soil that's too rich or they stay squat and start flowering at week 5. You'll end up with a tent full of quarter ounce midget plants.

suba.nakni said:

Light is 48" at 50%, watering every 2 days. Mendo Mix is what the shop recommended. I will start again,
Thanks for your quick replies.

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4' at 50% makes it 150W at 4' which is probably around 200 PPFD, so you're good, but it's not a bad idea to measure PPFD, even if it's with something like the Photone app for iOS.

Every two days at that stage and temp/rh is overwatering, which is why it's showing a nitrogen deficiency and causing the growth to stall.

If you really wanted to, you could back watering down to once a week (or however long it takes for the pot to be feather light when you lift it), but you're already starting behind the 8-ball - but this could be your learning grow, realizing that you're just using it to get your growing skills better and taking it out on as few plants as you can.

Keep in mind that once leaves yellow, they're not getting their color back so you have to keep an eye on the other leaves to see if a remedy is working. Nitrogen pulls from the bottom of the plant so the next set of bottom leaves would show signs next if a remedy is not working.

Definitely overwatering, Mendo mix is a coco based potting soil, it has added nutrients, good for about 4 weeks before you need to fertilize.

Thanks everybody for the advice, I will be starting again soon.

suba.nakni said:

Thanks everybody for the advice, I will be starting again soon.

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I think you been verwatering and the soils a tad hot use seedling compost or a light mix next time bud

Updates
I have got new seeds germing, placed the 2 WW auto in a 5 gal pot and try to learn from this grow. Not sure how to read light meter, says 1145, light is 48" away at 40%.
2nd grow is gonna be DWC using Lucas formula, should help with watering issues.

suba.nakni said:

Updates
I have got new seeds germing, placed the 2 WW auto in a 5 gal pot and try to learn from this grow. Not sure how to read light meter, says 1145, light is 48" away at 40%.
2nd grow is gonna be DWC using Lucas formula, should help with watering issues.

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Pretty sure the par has to be between 100-300
But here's a lux to par meter https://www.waveformlighting.com/horticulture/convert-lux-to-ppfd-online-calculator

suba.nakni said:

Light is 48" at 50%, watering every 2 days. Mendo Mix is what the shop recommended. I will start again,
Thanks for your quick replies.

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Piece of advice - disregard what the “shop “ recommended. They only want to sell you items.

Grow your weed like a tomato plant - literally.

Autos can run on regular potting mixes like ocean forest - no “ boutique “ soil blends. Just a precharged ( nute ) garden soil. FFOF can power your plant for weeks on water alone. Most autos need around 100 days ( + or - ) and simple feeding requirements.

Start over.

I have started my autos in Coast Of Maine soil with lobster and I add bat shit, chicken shit, earthworm casing, more lobster and crab shells with a little bit of kelp. I don't feed them for 4 weeks and since I had medical issues they got fed less overall but still came out tasty.
Start my outdoor plants in same mix but the tiers I plant them in are all composted manure with lobster and crab shell added