Leaves curling up with good humidity and temps – should I be worried?

Hello everyone!

I tried searching but I'm still not sure if there is a problem or am I being paranoid. Both plants are autoflowers, Fast Eddy CBD from Royal Queen Seeds and Jack 47 Auto from Sweet Seeds.

They are at day 11-12 (Jack sprouted after 45h only, Eddy around 70h) from breaking through soil and look like this:



Pics taken after 4 hours of darkness if that makes a difference.
Disregard uneven coloration, they are evenly green (just bad lightning).

I'm worried about the curling that is getting worse on the old leaves, and happens slightly on some newer ones too. I've seen multiple grows here with similar leaves in the early stages that were commented on as "looking great" so not sure if that's a problem.

Soil: BioBizz Lightmix with about 30% perlite added, 11l pots with good drainage
Watering: 220PPM tap water, left in buckets for ~48h, 6.5 PH, no nutes so far
Light: 250W HPS (Osram PlantaStar DUAL) 20/4 cycle, 40 cm above
Temps: ~23-27C (usually 25.5C), night ~19-22C
Humidity: 50-65% RH, slightly higher at night
Tent: 60x60x160cm

The roots started poking out through the bottom if that matters.

When I place my hand over the plants I feel pretty much zero heat, the mist from humidifier + wind from the fan provide a cool breeze.

One thing to note, there is a small non-oscillating fan pointed directly at the plants pretty much 24/7. When I place my hand in front of the plant, the wind is pretty subtle but it makes the plants dance/shake a bit – is that a problem?

I don't think I'm over watering, they were only watered three times so far, after pots were light and dry even from the bottom.

Any advice on when to start feeding? They are growing really fast as far as I can tell so I'm hesitant.

Sorry for the wall of text, but this being my first grow ever I'm stressing about every little thing!

Hope I provided all the relevant info, looking forward to your replies.

How close is the light

Little over 40cm.

I removed the mixing fan and added a small intake fan that blows 23-24c air from the outside gently at the plants, hope this will help with the curling.

A subtle breeze is not likely to cause that look, it's usually the light being to close.

Is the light air cooled with the heat ventilated out of the tent?
If not I would move the light a little higher maybe 45cm.
Might help take some stress off the plant if you also adjust the lights from 20/4 to 18/6.

There is no cooltube at all, only an intake fan takin 22-24C air in and exhaust.

I moved the lights up a bit to around 45-50cm, maybe higher.

Do you think it's a major issue? They seem to be growing really fast besides the curling. Also, when should I start feeding them?

Automatix said:

There is no cooltube at all, only an intake fan takin 22-24C air in and exhaust.

I moved the lights up a bit to around 45-50cm, maybe higher.

Do you think it's a major issue? They seem to be growing really fast besides the curling. Also, when should I start feeding them?

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They have good color and the new growth looks good so I don't think it is a major problem or caused any problems. Those leaves may continue to dry out around the edges from the damage that was already done.
Follow the new growth, if it doesn't curl you should be OK.
Never used BIOBizz so I can't guess on when to feed.

Kushash said:

Those leaves may continue to dry out around the edges from the damage that was already done.
Follow the new growth, if it doesn't curl you should be OK.

Click to expand...

Thanks, that's reassuring.
I was away for 2-3 days, left them with just 4 small leaves and came back to much bigger plants, but the temp went up to around 33C for last 12h or so, with low humidity too - maybe still suffering from that.

I check on them every two hours or so and they keep growing by the hour so I guess there is not much to worry about!