Anybody know what's causing this?

[dostrander]

Plants were fine in veg, switched them over to the flower room, two days later the leaves are starting to curl downward along the sides turning them tubular.

 

[SxIstew]

By the looks of it. mix of heat and possible under watering.

[h=1]Solving Marijuana Plan Leaf Curl/Cupping Problems[/h] Plenty of first time and experienced marijuana growers will suffer at some point in their cannabis growing career marijuana plants that begin to show leaf damage.
Often they write emails or post on forums.
“Help, my leaves are cupping and the leaf edges are turning brown!”
or
“My plant's leaf tips are curling down and turning black ....what's wrong?”
Unless another marijuana grower inspects the damage a true assessment might not be possible. It's hard to tell "exactly" what the culprit is. Unfortunately the “solution” the marijuana grower chooses many times is not the right one.
A misdiagnosis only serves to make matters worse by promoting further decline.
The ultimate and correct solution is in the hands of the marijuana grower.
Here are some common problems when marijuana leaves are curling.

1. Too much marijuana fertilizer
   The most common cause of marijuana leaf cupping aka leaf margin rolling, leaf margin burn, and leaf tip curl/burn is overzealous use of marijuana plant food. In relationship to factors such as marijuana plant vigor and rate of growth. Leaf burn is often the very first sign of too much marijuana fertilizer.
   A hard, crispy feel to the marijuana leaf frequently occurs as well, as opposed to a soft and cool feel of a happy pot leaf. Back off on the amount and/or frequency of using marijuana fertilizer. Too much marijuana fertilizer can also burn the roots, especially the sensitive root tips, which then creates another set of problems. Note - as soil dries, the concentration of the remaining salts rises further exacerbating the problem.
2. High Heat
   The marijuana plant is losing water via it’s leaves faster than what can be replaced by the root system. The marijuana leaf responds by leaf margin cupping or rolling up or down (most times up) in order to conserve moisture. A good example is reflected by the appearance of broad-bladed turf grass on a hot summer day, high noon, with low soil moisture levels - the leaf blade will roll upward/inward with the grass taking on a dull, greyish-green appearance. Upon sunrise when moisture levels have returned to normal, the leaf blade will be flat. Lower the heat in the marijuana grow-op and concentrate on developing a large robust root system. An efficient and effective root system will go a long way to prevent heat induced pot leaf dessication or marijuana leaf margin curling. One short episode of high heat is enough to permanently disable or destroy leaf tissue and cause a general decline in the leaves affected, which often occurs to leaves found at the top of the cannabis plant. The damaged pot leaf (usually) does not fully recover, no matter what you do. Bummer in the summer. One can only look to new growth for indications that the problem has been corrected.
3. Too much light
   Yes, it’s true, you can give your marijuana plant too much light. Cannabis does not receive full sun from sunrise to sunset in its natural state. It is shaded or given reduced light levels because of adjacent plant material, cloudy conditions, rain, dust, twilight periods in the morning and late afternoon, and light intensity changes caused by a change in the seasons. Too much light mainly serves to bleach out and destroy chlorophyll as opposed to causing marijuana leaf cupping, but it often goes hand-in-hand with high heat for indoor marijuana growers. Turn down the time when the lights on in your marijuana grow room. If you're using a 24 hr cycle, turn it down to 20 hrs. Those on 18 - 6 marijuana growth cycle can turn their lights down two or three hours. Too much light can have many adverse effects on marijuana plants. Concentrate on developing/maintaining an efficient and robust root system.
4. Over Watering
   For marijuana growers using soil, this practice only serves to weaken the root system by depriving the roots of proper gas exchange. The marijuana plants roots are not getting enough oxygen which creates an anerobic condition inducing root rot and root decline with the end result showing up as leaf stress, stunted growth, and in severe cases, death. Over watering creates a perfect environment for damp-off disease, at, or below the soil line. Many times marijuana growers believe their cannabis plant is not getting enough marijuana fertilizers (which it can't under such adverse conditions), so they add more marijuana fertilizers. Making the problem worst. Not better. Often problem 1 and 4 go together. Too much marijuana fertilizer combined with too much water. Creating plenty of marijuana plant problems.
5. Not Enough Water
   Not only is the marijuana plant now stressed due to a low supply of adequate moisture, but carbohydrate production has been greatly compromised (screwed up). Step up the watering frequency, and if need be, organic marijuana growers may need to water from the bottom up until moisture levels reach a norm throughout the medium. One of the best methods in determining whether a marijuana plant requires watering is lifting the pots. The pots should be light to lift before a water session. After watering the marijuana plants lift the pots to get an understanding how heavy they've become fully watered. If the pot feels light to the lift - it’s time to water. Don’t wait until the soil pulls away from the side of the pot before watering. And of course, leach, once in a while to get rid of excess salts. These are the five most common problems marijuana growers encounter when growing cannabis. Correcting the problems early will save the marijuana plants, but may reduce overall yield. With practice and experience these problems are easily overcome which will then enable the marijuana grower to produce fantastic marijuana plants. With heavy yields.

 

[dostrander]

By the looks of it. mix of heat and possible under watering.

Thanks for the reply stew.

Well, the plants aren't wilting, cupping I've usually seen goes 90 deg to that. The feeding schedule I have them on is every 4 daytime and once during the night, and the temp is kept at 75.

To address the other issues in your quote;
1) They're in their first week so I started them off at about 600 ppm with the PH at 5.8
3) There are 2 600 Watt lights covering about 25 sq ft (1 HPS, 1 MH), distance kept about 18 inches and of course at 12/12.

 

[SxIstew]

Well. That all sounds correct....

Apprears Hydroponic, so.....
How's your reservoir? do you clean it weekly?

Any thing that may cause a slight over fert issue?
Not sure of anything else it could be other that.

You sure it's not for the less frequent watering at night?
Another member here a few days ago, realized his water pump was on the same timer as his light and shut off at night. His plants were cupping and starting to wilt. but just looked droopy not wilted.

Check you res. check your roots.
If both are OK then i don't see what could be wrong buddy..

Good Luck.
Anything more, just post any myself or someone should be able to help.
Stew

 

[dostrander]

The res's I clean at about 7-10 depending on how they look. In the buckets I keep the hydroton at 2+ inches above the water line and the res's are sealed and in the dark so I never show any signs of growth at all.
Since they're at 600 ppm I don't see how it could be over fert. I've been using GH Duo, Cal-Mag, Pro-Silicate and Hygrozyme, I'm wondering if maybe one of the nutes has gone bad (although I've not heard of anybody having that problem and wouldn't know how to tell) so I'm going to drain it and just go with the GH duo and see what happens.

 

[SxIstew]

Good luck..
FloraDuo is a very HOT product, I've killed plants with it.. so be sure to keep an eye on your PPM/EC/pH..

later bro... Let me know if it gets worse. we can figure it out at some point.