Dark Green, Droopy Plant

Hi Guys,

Please take a look at the attached pictures. 1 of my seedlings is looking far less happy than the rest, it appears to be a far darker green and the leaves are very droopy. I'd be tempted to say it is being over watered, but they are all on the same watering schedule and I know the weight of the rockwool and water it when it is down to the last 15-20% of water.

Please ignore the discoloured lower leaves, that was due to being too close to the light when it was very young (2 weeks ago) but the plant seemed to recover and is now showing these symptoms. The new leaves are showing no discolouration.

I'm currently feeding them a half strength grow solution which I've moved up from 1/4 strength recently.

The grow space fluctuates between 70 and 78 degrees with the light on, humidity is below 20% (could this be the cause? only thing is most of the other plants seem fine). I currently have them under a 600 watt dual spectrum HPS that's sitting around 22 inches above the plants. There still appears to be new growth coming through I'm just concerned with the droopy leaves.

On a slightly different note, is this plant a reasonable size for 3-4 weeks from germination? Also seems a bit small to me.

Thanks in advance guys.
st0nepac

overwateered mate

STOP the nutes ther too young,just tap water

so its nowt to do with humidity ect ther just not strong enough fornutes and your watering them wayyy to much,,hll i only water my littlens once a week

I'm confused st0nepac, why is there a peat pellet in a rockwool cube? Those two hold water a little differently to each other and it seems like it would give you trouble when they are young. I would hate to put that into my hydro as it would muck the reservoir up.

IC3M4L3 said:

overwateered mate

STOP the nutes ther too young,just tap water

so its nowt to do with humidity ect ther just not strong enough fornutes and your watering them wayyy to much,,hll i only water my littlens once a week

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Hey thanks for the reply. I water the plant when it gets below 20% of the difference between its wet and dry weight, if i leave it any longer the cube would dry out completely which is bad I've read?

As for the nutes, it's 3 and a half weeks old since sprouting and it is in rockwool. Everything I have read says they should be getting very diluted either quarter or half strength nutrients by now.

If someone could clarify those 2 points I would really appreciate it.

fxbane said:

I'm confused st0nepac, why is there a peat pellet in a rockwool cube? Those two hold water a little differently to each other and it seems like it would give you trouble when they are young. I would hate to put that into my hydro as it would muck the reservoir up.

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Hey mate it's a rapid rooter, guy in the hydro shop said they're fine to go straight into the rockwool and i've seen lots of other people do it. Should be fine afaik.

st0nepac said:

Hey mate it's a rapid rooter, guy in the hydro shop said they're fine to go straight into the rockwool and i've seen lots of other people do it. Should be fine afaik.

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My bad, I blanked out on the rapid rooters for a moment there.