k/mg deficiency?

[bbkingwithaj]

I need some help identifying what's wrong with these plants, this is my third grow so I almost know what I'm doing and I'm thinking it's either a k or mg or possibly both deficiency.

It started with the edges of the plants turning a really light green, then the tips started to burn a little and eventually droop, now the tops are looking kind of stunted, they're twisting a little alkwardly.

Please let me know what you think, I've never had a problem this bad and I hope it's fixable...

edit- Sorry the picture quality is awful but it's all I had.

 

[bbkingwithaj]

Sorry, first post in a while, here's more info:

There are 4 indoor clones in soil, mostly indica strain in veg for about 3 weeks. Don't remember exact soil mix, just used out of the bag fertilized plant soil from wal mart, in 8 gallon pots. They are under a 1000w hps light and kept around 84 degeree's farenheit. It's a small area, just 8x8 we watered them with regular strength fertilizer for their 3rd week.

 

[HB Rob]

out of the bag fertilized plant soil from wal mart

watered them with regular strength fertilizer for their 3rd week

Don't fertilize until they need it. You're looking at nute burn and beginning stages of pH imbalance. The pH of your soil will become more acidic as the bark or moss used in the potting soil breaks down. You'll need a well-chelated fertilizer as they'll drift farther out of the optimal uptake range or you can try replanting into soil with dolomite/Agricultural lime @ 1-2 cups per gallon of soil.

 

[bbkingwithaj]

Thanks for the reply Rob!

I just have a question about your post, I am a little confused about what exactly 'chelated fertilizer' is and google searches aren't doing a great job explaining it. Is there possibly a product you could recommend?

Also in the interest of full disclosure, read on for an exact description of my fertilization schedule.

Recieved the clones about 3 weeks ago. They were approx. 8 inches already, fed them with a quater strength 1st week fetilizer mix and transplanted them to 4 gallon pots. They were transitioned to a 1000w hps light over the next 3 days. After about a week they needed watering so I gave them the manufacturers reccomended nutrient intake recommended for week 2. Note now it's only been 10 days since I got these plants. At this point the plants begin to get sick, they start getting really bright green around the edges and a lower leaf is turning a little yellow with a couple tiny orange burn marks, this gets a little worse over the next 7 days, not too noticably. I then add week 3 recommended fertilizer to the bucket and water the plants for a third time. The plants took a turn for the worse, every leaf had the bright green outline, and was curling a tiny bit at the end, there was more noticable yellowing of the lower fan leaves, larger burn marks. Even the tops started slowing down, twisting alkwardly, not growing out like normal leaves, almost stunted...and then I posted these pics online.

 

[HB Rob]

Tough question for me right now. I'm medicated but I'll try my best.

Chelates are salts used to hold necessary elements for plant growth. They are designed to seperate and release elements in their available forms at different pH levels so that your plant will always get say nitrogen from some combination of those salts breaking down.

Ex: Ca+1 might break down at normal pH levels while Ca+2 may be known to break down at 7.0 so if your soil starts getting alkaline it'll still have a source of Ca ions.

they start getting really bright green around the edges and a lower leaf is turning a little yellow with a couple tiny orange burn marks

I have personal experience with this. It's lack of nitrogen due to either lock-out or plain lack of it. Edges are losing their green color (chlorophyll dying) because that is the farthest plant material for vascular tissue to maintain with fresh N. If it's not lock-out yet it will be. Sorry to say you may find it easier to start fresh with a quality soil rather than power through a bad situation. Cannabis is one of the heaviest feeding annuals around. Getting quality products in the beginning will go a long way in keeping the headaches at bay.

 

[bbkingwithaj]

Getting quality products in the beginning will go a long way in keeping the headaches at bay

True that, I've used a good soil before and I never ran into problems like this. So one last stupid question, as my plants are about 3 weeks in now, I have no idea what the root growth will look like. They were transplanted to a large pot(11 inches high, 11 inch diameter, don't know how many gallons that is) almost right away in the crappy soil, and have had 2 weeks to strech out. Is it even possible to transplant at this stage?

Or does start fresh mean get some new plants?

 

[HB Rob]

You won't know until you try. Water thoroughly. If you can keep the roots intact without losing too many chunks they should make it.

 

[PetFlora]

Chelates are a more bioavailable form of nutrients. As such, they are available over a broader range of pH.

hth