Help to identify this problem

Hi! I have 4 OG Kush vegging and they look okay except for one thing.

This is how they look just after 18 hours with lights on:



Same plant after 6 hours in darkness:



Leaves rise again but still I'm getting the same tacoing effect.

More details: RH 55-65%, 2x15 min feeds (1 before lights off and 1 within the first hour of lights on), temps 20/25C, PH 5.8, the bulb (400w HPS) is hanging 40cm over the top of the plants and I've already tried moving it away/closer.

More pics:

Before lights go off:



After lights go on:




Thank you.

This is the exact reason I dislike running an "all in one" system.. I like to use DWC in separate buckets so that when problems come down the pipe.. It's just one plant I have to take care of. Not all plants like the same treatment even from the same batch of seeds from the same plant. Unless you're running clones, which then they tend to all have the same requirements as they are more in kind to each other.

I find in systems like these that one or two plants will uptake nutes faster than other plants and will starve them. It creates too much competition between plants and its going to throw you PH out of whack faster. I find (for me) that these systems are extremely hard to keep balanced and trying to constantly run down new problems that arise. If you get any mold, it takes out the entire system...

For me in a small set up separate buckets have always worked better.

Obviously in a large set up you can't do it this way.

As I said in another thread - "It's pretty common for drooping and rebounding."

Wufi said:

Hi! I have 4 OG Kush vegging and they look okay except for one thing.

This is how they look just after 18 hours with lights on:

Same plant after 6 hours in darkness:

Leaves rise again but still I'm getting the same tacoing effect.

More details: RH 55-65%, 2x15 min feeds (1 before lights off and 1 within the first hour of lights on), temps 20/25C, PH 5.8, the bulb (400w HPS) is hanging 40cm over the top of the plants and I've already tried moving it away/closer.

More pics:

Before lights go off:

After lights go on:

Thank you.

Click to expand...

Google this. why do marijuana plants droop just before lights off?
Google is your new friend, RIU is full of wanna be master gardeners.

I personally think they are getting a bit too much nitrogen or the lights are a little too close to the plants.. The outer edges of the leaves are curling up, which can be a sign of too much heat or too much nitrogen or a little of both in younger plants. The over all temperature of the room might be cool enough, but the plants are too close to the lights? 40cm is 15 inches....

Some will argue with me but, that might be a little too close for younger plants. Thats why I love running T5's so I can set the light right on top of them practically, and get very little internode space. Then once they get 1 or 2 sets of "true leaves with a proper set of finger and size" I put them under the 400w, they are a little better able to stand up to the heat stress.

NrthrnMichigan said:

Google this. why do marijuana plants droop just before lights off?
Google is your new friend, RIU is full of wanna be master gardeners.

Click to expand...

Can you say? "Light saturation point in C-3 plants?"

Galwaith said:

I personally think they are getting a bit too much nitrogen or the lights are a little too close to the plants.. The outer edges of the leaves are curling up, which can be a sign of too much heat or too much nitrogen or a little of both in younger plants. The over all temperature of the room might be cool enough, but the plants are too close to the lights? 40cm is 15 inches....

Some will argue with me but, that might be a little too close for younger plants. Thats why I love running T5's so I can set the light right on top of them practically, and get very little internode space. Then once they get 1 or 2 sets of "true leaves with a proper set of finger and size" I put them under the 400w, they are a little better able to stand up to the heat stress.

Click to expand...

That has nothing to do with N.
Heat? Possibly a factor but >>>
Um, see the size of the plant?
Bet they haven't even set their roots in that pot yet.....

When I did hydro (soil rules ). I set my seedlings in 3" Rockwool cubes. Let them run in those till roots show on the bottom. Then into my ebb buckets....

Dr. Who said:

That has nothing to do with N.
Heat? Possibly a factor but >>>
Um, see the size of the plant?
Bet they haven't even set their roots in that pot yet.....

When I did hydro (soil rules ). I set my seedlings in 3" Rockwool cubes. Let them run in those till roots show on the bottom. Then into my ebb buckets....

Click to expand...

Whatever you say dude..... Coming from experience. If they haven't set roots in their pots yet(as a seedling I don't know how this would be possible, thats kind of fucking stupid)....

at any rate... If they haven't set roots in the pots yet, they're being over nuted and leaf edge curling up like that is a sign..

Don't worry young pup, you'll figure it out in coming years after you and NrthrnMchgn grow a few more hairs on your nuts.

I have four RQS Northern light in dwc that did the same thing about 2 hours prior to lights out during veg. They were always back to normal by the time the lights came back on in the morning. This stopped once they were switched to 12/12

Doesn't look too much N to me, looks they're anticipating lights off to me. Might want to move your light up a little higher too.

Would it be a good idea to progressively change the light cycle to 16/8 for the rest of the vegging period? I think it would help with temps and not over saturating the plants with light

Im thinking high temps, perhaps even humidity at 65% may be a touch high and plants are not transpiring the same way, so they appear limp. The curling of the edges in that manner and only the top of the plants, and mainly after being in the condition all day, they appear overly limp, suggests it's the environment. Lights on, looks good. May also want to back the light up..it's as if the leaves are turning away from the light trying to reduce the amount coming in..it may be a bit too much this early?

His humidity is no where near to high, infact it's just in the right range on the low side, that is if you believe in vpd.

As for plants getting starved in a recirculating system, poppycock!

Galwaith said:

Whatever you say dude..... Coming from experience. If they haven't set roots in their pots yet(as a seedling I don't know how this would be possible, thats kind of fucking stupid)....

at any rate... If they haven't set roots in the pots yet, they're being over nuted and leaf edge curling up like that is a sign..

Don't worry young pup, you'll figure it out in coming years after you and NrthrnMchgn grow a few more hairs on your nuts.

Click to expand...

If you took offense to what I have written,... then you must be one of those master gardeners I was referring to.

Wufi said:

Hi! I have 4 OG Kush vegging and they look okay except for one thing.

This is how they look just after 18 hours with lights on:

Same plant after 6 hours in darkness:

Leaves rise again but still I'm getting the same tacoing effect.

More details: RH 55-65%, 2x15 min feeds (1 before lights off and 1 within the first hour of lights on), temps 20/25C, PH 5.8, the bulb (400w HPS) is hanging 40cm over the top of the plants and I've already tried moving it away/closer.

More pics:

Before lights go off:

After lights go on:

Thank you.

Click to expand...

How may times are you feeding the plants per cycle. I recommend 5 times per light cycle 18/6 and 4 for 12/12. Timer is set on 15 minutes for the fill and drain I hope. The plant in the first pic looks droopy due to lack of water. The roots are not enough to sustain the plant between waterings. Your in hydro you always want to keep the roots wet or else they get dry and it stresses the plant.

Top feed the plant to help make sure the roots are wet till they grow enough to get lower in the pot.

And yes they droop before lights out. Taco could be from light/heat stess, raise light up another 6 inches and or 3-4 feet away till they get bigger and can handle it.

Galwaith said:

Whatever you say dude..... Coming from experience. If they haven't set roots in their pots yet(as a seedling I don't know how this would be possible, thats kind of fucking stupid)....

at any rate... If they haven't set roots in the pots yet, they're being over nuted and leaf edge curling up like that is a sign..

Don't worry young pup, you'll figure it out in coming years after you and NrthrnMchgn grow a few more hairs on your nuts.

Click to expand...

Oh, to insults straight away.

I've done this, most likely longer then you've been alive.

It's more likely you, don't understand exactly what "root set" is.

The simple answer is to simply wait a while and watch the new growth for issues. As the roots set in the media to where they are comfortable....The "issue" will go away.

I would agree with Bernie on running 5 floods a 24 hr period....So increase the floods and wait......