Middle of leaves cupping up and yellowing

ZeHgS2

Active Member
You can't see it very well on the pictures but the oldest leaves of both my White Rhino and Super Silver Haze plants are starting to get yellow and dry, and their middle is curling up. It is also starting to spread to the newer three-bladed leaves. They are both 18 days old, growing from seed. The soil is just some organic one I bought at the supermarket and they've been there since they germinated. The containers are about 4 gallons in volume. They are each about 20 cm in height. Haven't used any nutes yet. I water maybe every 2-3 days as necessary and I give them about 500 ml each time. I unfortunately don't have a ph meter. Oh, and the lights are on 24/7 (HPS 150watt) and about 40-45 cm from the plants. I don't know the relative humidity either, or the temperature but it doesn't seem to get very hot near the plants. I'm growing them in a closet and they don't get that much ventilation except from the times I open the doors to look at them (which happens at least 6-7 times a day). I also have a white widow plant growing in the same closet but I doesn't seem to have been affected yet. I'm using tap water that I let sit for a day or two to get rid of the chlorine. I haven't seen any bugs yet. I think that's all I can think of to tell you guys. Please help my ladies =(View attachment 1141460View attachment 1141459View attachment 1141458View attachment 1141457View attachment 1141456View attachment 1141455View attachment 1141463View attachment 1141454


ps.: all the pictures are from my white rhino plant
 

ZeHgS2

Active Member
Damn it, it's getting worse and I think it's starting to affect my White Widow too. It's gotta be the soil I think, since it's the only thing they all have in common. What should I do? :(
 

patlpp

New Member
Foliage feed one with some 3-something-something nitrate based nute and see if it improves. If it does, they are starved. Some soil is just dirt, near dead dirt.
 

ZeHgS2

Active Member
Ok, I will try that. Are the damaged leaves supposed to recover after I do that or are they just gonna stop getting any more damaged and remain looking like they do?
 

ZeHgS2

Active Member
Any other ideas of what might be causing the problem? The leaves are getting drier by the minute, I think it's not gonna be long till they fall off. And the white widow is also definitely affected. It HAS to be the soil, right? I mean, what else could it be?
 

BlasphemyFloyd

Active Member
Soil can be the problem. You need to set your waters ph at 6.5 for soil (I'm sure you heard this before) and will definitely need to get yourself a ph meter/tester. Dont bother getting a soil tester (they are useless for this application) or those colored water testers (quite inaccurate if you are a novice). Also, get yourself a good, expensive one. DO NOT get those cheap Chinese made garbage they sell on Ebay (the red or yellow ones, they are really a pain to work with and made with shoddy parts a.k.a sawdust and Oreo cream filling :P) Get something from Hanna or HM (really recommend HM, they are awesome).

Why ph? Because ph is almost ALWAYS the culprit, it can lead to lock out and false postitives for different deficiencies. Dont feed it any nutes till you fix the ph or you will be SORRY :(...
 

ZeHgS2

Active Member
Damn it =( I wanted to spend as little money as I could, but I know a PH meter essential. I think I'm gonna have to buy one as soon as I can. Could it be anything else?
 

GrowBank

Member
Usually leaves that are "praying" or "cupping upward" are caused by magnesium deficiencies.

Add some Cal Mag to your nutrients and make sure to PH to 6.2-6.5 in early veg growth.

I would start with correct PH and minor cal mag additions, see how they recover.
 

ZeHgS2

Active Member
Damn they are getting worse. I'm afraid they might die if it keeps up like that. I'll try first adding the nutrients and if that doesn't work I'll buy a pH meter. Thanks
 

ZeHgS2

Active Member
Are the leaves gonna recover their healthy aspect once I fix whatever is wrong or is just not gonna get any worse?
 
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