What could be causing this?

[rwdyredhead]

Most of the time my plants get real droopy about 3 to 4 hours before lights out. They start to droop in the evening and it gets worse until some leaves are actually resting on the ones under them. They're on 18/6 with 3 40 watt cfls on the two plants plus they're getting side lighting from 2 other 40 watts that are on some seedlings(total probably 160 watts on 2-22 day old plants). I know you're supposed to get the bulbs real close but every time I get them closer that about 5 inches it seems to affect the plants in a bad way. They don't seem to take it well. I keep the temp between 73 to 80 daytime and when the temps get over about 77 degrees I use a small fan to blow cool air over the tops to move the plants and keep the heat off of them. I'm constantly trying to keep the humidity up but it stays around 45 to 55 during the day and 55 to 65 at night. The largest fan leaves just look dry and limp with the stems completely curved downward. The next morning they always look better but sometimes still a little droop. A few nights ago the temps dropped to 66 degrees at night by accident and the plants looked amazing the next morning, standing straight, leaves pointed towards the sky like I've never seen them. They seemed to love it. ???

[rwdyredhead]

Oh, I'm definitely not over watering either. I make sure they're dry an inch and a half down before watering.

[DrPhoton]

I really wouldnt think nutrients had any part to play in this tbh. Turgor pressure is whats responsible for plants drooping and standing taught. This pressure is governed by the amount of water being transpired and uptaken through the roots. Any imbalance in this flow will disrupt or change the turgor pressure.

[rwdyredhead]

Thanks for the suggestions. I have 2 more 40 watt bulbs coming in the mail right now. I've been adding them as they grow but I have 3 new 1 week old auto seedlings in 3 gal pots now which spaced my lights out a little further than I intended but still a good bit of light. They're getting nutes every other watering at 6.0 and checking the run off every time. One of the two had some brown spots last week and the ph was a little low so I bumped it up a little and that fixed it.

[StoneyTony]

I've encountered the same problem before in a grow. It turned out it was a combination of pH and heat from the lights.

[DrPhoton]

The night time recovery could be a clue, at night humidity is higher due to lower temperatures. During the day humidity is lower and so plants will uptake and transpire more water, higher humidity at night slows uptake and transpiration. I am thinking there is something wrong with the soil/roots, not being able to absorb the water it needs.
How often and how much do you water ?, what type of soil are you using ?.

[rwdyredhead]

They're in coco. It's like the light/heat and light breeze just takes it out of them after 14 hours or so. To water I go by the feeling of the pot, when it feels light and also make sure the top inch+ is dry then I water until it runs out the bottom of the pot at least 20% of the water. They're going about 3 days in between watering.

[DrPhoton]

Coco coir is a fantastic soiless product, but people usually mix it with other mediums to get the right balance of everything.
Although coco holds on to moisture really well, it also drains really well too. It has higher resistance to over and under watering. But i think in this case it may be underwatered, as you say you are more than likely not overwatering so giving it more water to find out should not hurt. I would water it for the next two days, then every second day until effect.
Coco also developes excellent roots because of how well oxygen and water is available to them, although the plant is in no way big for the pot. Check the roots to see if there is root bound going on. Unlikely but iv had root bound in small plants before causing drooping.

It may be possible that your lights are too hot, i had a similar problem with clones and decided to use LEDS instead for less heat. I dont think the wattage is a problem as the plants dont appear to have light stress or underdeveloped growth.

Let me know how you get on.

[rwdyredhead]

I went back and looked at my notes, they've been in the 1 gal pots for 12 days and have been going 4 days in between watering. Actually, now that I think about it, they do have some drooping on most days but they have bouts of sudden severe drooping like they did yesterday. I haven't kept track of when it happens but I just realized that it might be coinciding with being watered. This happened about 24 hours after being watered. So, I let them dry out pretty well and they were looking great, then I watered them and the next afternoon they suddenly look like limp noodles.
The dry soil in the pic is the sides of my 3 gal auto seedlings. I only water them around the middle of the pot so the edges stay dry.
They have really taken off since transplanting from solo cups, could they be root bound in 12 days? I'm going to check today. I was hoping to top them in a day or two but I hate to chop them if they're stressed at all. What do you think?

[rwdyredhead]

Here's some pics of them this morning. They always perk back up overnight but when the droop is bad they aren't able to recover completely by morning. What do you think about misting them with a spray bottle during the day?

[kingfish]

Rwdy, I'm dealing with RH of 20-30% all the time. I don't even worry about it. I have humidifier running 24 hours a day and I can't raise the humidity. By looking at your plants, I don't see a thing wrong with them. I'm always leery about spraying anything on my leaves, unless I'm invaded by bugs. Keep a fan blowing on them always. Don't blow the leaves off them, just a constant light breeze.

[insomniaczzz]

Do check to see if root bound. one gallon pot isn't very big. We had ours in 2 gal pots, and thought that would get them through to harvest. Wrong, they became severely root bound and ended up transferring to 5 gal buckets about two weeks into flower stage.

[rwdyredhead]

Here's what had me stumped...a pic of them side by side from yesterday evening and then around noon today. Sometimes they just seem to droop drastically in just a few hours. I look in there and I'm like "what the !#%*&@" lol I know a little drooping happens at night but could this much be normal? They look great today tho!
Unfortunately I ran into another more concerning issue when I was taking pics earlier.
Two of my auto seedlings have brown spots on the edges of the leaves. I've been watering around the plants (6.0ph) and halfway to the edge of the pot when the coco feels like it's getting dry but I stuck my finger in one of the big drain holes at the bottom of the 3 gal pot and the soil is moist at the bottom edge. I can't really check the ph when it's already too damp can I? I've been giving wk 1 nutes (GH) from Nebula's schedule on GWE and CalMag every other watering. They are 7 days old.
PICS BELOW, it won't let me post them here.

[rwdyredhead]

insomniaczzz I wish I would have put them in bigger pots but they were so small in solo cups just 12 days ago. The 1 gal looked big then! lol This is my 1st time growing weed and I was worried about the "little plant/big container" problems with watering. I figured I'd transplant them again later because I'm pretty experienced at transplanting from working with regular plants. I had never used coco before tho. It's warming up outside so I'll take them out and check the roots soon. Thanks for your help!

[StoneyTony]

I agree with insomniaczzz, strong possibility they are very pot bound.

[steve]

More light (plant is being starved ) Or move closer to light, then water till soil is moist to the touch

[rwdyredhead]

[Lotusyde]

NebulaHaze your help is needed. I've never used cfls. Maybe they are too close?

[South Sierra Dude]

I've grown in straight coco and had the same issue. I increased water from one gallon every day or two to two gallons every two days. This was an out of doors high desert grow. I also put sails up to shade the root balls. Turgidity returns in seconds when the coir is watered thoroughly. Hope my experience helps; I know it can be frustrating looking for solutions.

[DrPhoton]

This is what i thought.

[rwdyredhead]

I used about 3/4 of a gallon combined on those 2 one gallon pots. I actually watered one of them twice because when I checked the run off water it had low ph so I bumped up the ph and rewatered it. In other words, I watered one until water ran out and the other until water ran out twice and both drooped exactly the same. It is frustrating but tonight they're doing much better, a tiny bit droopy but nothing like last night. I documenting when it happens now so maybe I can pinpoint the reason. Thanks for the advice from everyone, it really helps.

[DrPhoton]

It does seem to be a water issue of some kind, let us know how you get on.

[South Sierra Dude]

I am going to experiment with perlite and coco this spring to check effects on Turgidity.

[rwdyredhead]

I'd be vey interested in that.

[Green75]

I have 13 40 watt cfl's on my auto...she is loving it.

I don't think it's your lights....

Definitely need to cut some of those HUGE fan leaves off...you have no side growth going on.

You will notice huge change...

[rwdyredhead]

They are just growing they're 6th set of leaves so I'm about to top them. Can I safely take those big fan leaves off too? Is that too much at one time? I'm planning to top them once and do some lst as well. I was just reading on GWE about extensive defoliation and I'm very interested in that! That is my long term goal as well as going full hydro but this is my very first grow so I don't want to get in over my head too much. I started with 6 bag seeds and only 2 sprouted so I ordered 3 autos and also planted a freebie photo fem, so I have quite a variety going on for a beginner. Can I safely take a few fan leaves and top a few days later?

[Green75]

Take off the fan leaves Let each node grow a little more and then pick the healthiest strongest longest one to top down to maybe a week

[francis pharmer]

I've had certain strains that just do this 1-3 hours before lights out they start to droop and are back to perky in the a.m. I've switched the light from CFL to MH to HPS and it's the same no matter what. It happens to these strains no matter the environment, food or water. There's no problems with them otherwise. Not sure what the explanation for this is though.