Possible magnesium deficiency in nutrient film setup? Help appreciated

Hello im not new to this sight just new to posting threads and also a beginner at growing cannabis. I would also like to thank u ahead of time for the input you provide i actually do appreciate it. I purchased a grandaddy jack clone from my local dispensry. I brought it home and set it up in my nutrient film hydro system. Im around 2 weeks into the veg from when I put it in the system and im noticing the oldest leaf on the clone has a few yellow spots and is getting pale/yellowing between the veins. There are also some brownish spots at the end of the leaf. I have noticed the 2nd newest leafs edged curling up slightly. I maintain my ph between 5.8 and 6.2 and i use liquid carbon c02 booster, plant food from my local market ( 12%N, 4%p2o5, 8%k2o, .1% iron, .05% magnesium, .05% zinc), a 3ft channel, large airstone, and only a 75w 120v medium base grow light about 1ft 3 inches from top of plant.
Ive noticed the problem got more predominant today so i moved the light to about 2ft 3 inches away from the plant (incase that was the problem) and flushed the whole system with new nutes, water, co2 boot ect, making sure i kept the ph at about 6.4 ( incase magnesium deficiency). I also checked the roots. They seemed slightly slimy and only about half of the visible root was wet, the other half closest to medium was dry so i sank the net pot deeper into the channel so more of the roots would hit the running nute stream. The room gets adequate ventillation and the temperature is about 68-75. Any ideas on what my problem could be? Ill keep this post updated till the end to possibly help anyone else having the same problems. Thanks again for the help!

dont laugh at my reflectors to shine light from underneath

notice the yellowing between veins.....i know it doesnt look extremely bad but thats hopefully because it isnt yet......

Hi 6>4,
Like you say, it looks like magnesium deficiency. I have no experience with that strain. I had however similar problems a while ago with a White Rhino. The leaves indicated Mg and N deficiency. The picture of your clone looks much like my clone did initially. My PH fluctuated between 5.8 and 6.1. After a few weeks I discovered that the PH actually was between 5.7 and 5.9 most of the time. I raised PH to 6.0-6.2 and the plant recovered within about a week so the deficiency was probably caused by PH lockout.

My suggestion is that you monitor the PH closely and keep it between 6.0 and 6.2 until it recover to make sure that you don't have a PH lockout. Add low dose of CalMag to your solution. Also add H2O2 to get rid of the slime.



Good luck with your grow op!

It just looks like a clone that is recovering, they do that when they are first growing roots.

First relax and dont freak out. This is common in new clones. With no root system to support the existing grows, it's using the nuts it has already inside it to heal it's self. This will make it look lIke a deficiency. A clone is already stressed out, so don't go doing a bunch of stuff to it. Just give her a chance to grow some roots to support what she has, first. To be honest, from the pictures, she doesn't look like she has any roots at all.

The water should be ~5.5 pH for new cuts and raise to 5.7-6.3pH, as roots take hold. I can't tell if you're soil or hydro. If soil, once transplanted to soil, you can switch over to normal feed schedule and pH.

I also can't tell from the pictures, but I'd change the water often, if it's just a party cup of water. You don't want bad bacterial growth to build up. I recommend getting a fish bubbler and an air stone to help aerate the water.

Thanks ALOT for all the great information that i did not know! All you guys gave me helpful insight that will hopefully help other people also. @ dumme > its Nutrient film hydro and the pics r close ups of the cup sitting in the channel which is sitting above the nutrient reservoir (cant see in pic). I did not know that about new clones so thanks 3n1gm4 and dumme! and i also had a ph fluctuation so ill keep close eye on that and thanks for the recommendations mikeganja i was concerned bout the buildup. Im gonna keep updating this thread just in case anyones interested in results. =] thanks again everyone.

Keep in mind, clones don't need a lot of light. Those reflected juice packets won't really help you; making sure she's getting moisture is. She looks alright, but just know, without a root system, she relies heavily on humidity in you room and the method you used to cut. Some people even go as far as spraying the leaves with water and a humidity dome. Good luck with her.

I wouldnt recommend spraying the leaves directly as it can cause damping off(stem turns to mush, plant dies)
I only spray the dome when most of the visible water droplets have evaporated, this keeps the humidity at 100%

Keep your ph stable at about 5.8 to 6.0 for hydro setups. Ph is tne firdt thi g i look at now when i have a nute issue. If u ouing ro water or low tds water a good calmg suppliment is a must. Using a good cannabis nute li e goes a long way imo. Good old GH Flora is great and cheap, Dyna Grow, Botanicare all good nutes and all you need to do it right is veg, bloom and cal mag nutes.

i will spray around the plants roots. it is sitting above a water supply also. i figured the reflective packets wouldnt do much BUT when i remove them, i see shadows beneath the leafs covering undergrowth but with them there, the underneath of the plant IS getting reflected light i just thought that was interesting

keafy said:

Hello. I'm currently flowering a strain called THC Bomb from bomb seeds. I'm currently starting week 5 in flower. I'm using a Marshydro 1200w and 180w LED in a 5x5x7 grow tent. Using organic soil for my medium in a 10gl fabric pot and using General Hydroponics FloraNova Bloom/Liquid KoolBloom/Floralicious Plus and Epsom Salt for my magnesium.

Any suggestions? Comments? Would like to know any advice would help.

Happy Growing

Click to expand...

Yes, post your own thread.

This is her now. Roots less slimy forsure, but slightly brown due to staining i assume because she is still exhibiting great growth daily so i dont think root rot is an issue.... . I scrapped the reflective packets (lol) and covered the cup that sits in the channel with tin foil for reflection and to keep the rockwool out of the light. My ph kept rebounding, so i emptyd and refilled my nute reservoir with distilled water that starts out at bout 6.2 ph and doesnt rebound. I see more roots daily. Ive been keeping humidity high. You guys are a great help!

Hey guys! I told you id keep yall updated! This is her today. Doing GREAT! Using the flora series for nutes, and distilled water only, 24hr lights. I do however have 2 soil clones with problems now so if anyones interested check out my other thread i would appreciate all your help, you guys are very informative. THANKS AHEAD OF TIME!!!