First time grower: Troubleshooting plant problems

Hi all,

I'm having some problems with my first time grow and wondered if some of you experienced people could point me to the right direction in fixing them. The main problem seems to be blackening of the leaves. I've moved the light as far away as I can, and turned one of the two 50W Cree Cobs off completely, but that doesn't seem to be resolving the problem.

Closet space = 2x2
Lighting = Two 50W Cree Cobs (can only run them at full power, no dimmer available)
Nutes (All at half strength of recommended) =
Advanced Nutrients Micro/Grow/Bloom
Roots Excelerator
Mammoth P

First two weeks = no nutes (I hadn't bought any yet)

Week 3
Micro 1ml/Ltr
Grow 1ml/Ltr
Bloom 1ml/Ltr
Roots Excel 0.3/Ltr
Mammoth P 0.15/Ltr

Week 4
Micro 2ml/Ltr
Grow 2ml/Ltr
Bloom 2ml/Ltr
Roots Excel 0.3/Ltr
Mammoth P 0.15/Ltr

Notes:

When I first put them as seedlings under the light they soon after started looking burned. The light was around 2ft away. The leaves were shrivelling, so I moved the light up as far as I could (around 3ft). All three of the plants are showing various degrees of blackened leaves.

The girls get fed around every 3 or 4 days when the pots are very light to pick up.

I do plan to move two of the girls to a different much taller 2x2 closet space (200W Cree Cob with dimmer) when they're ready for the next transplant.

Strain 1
Icebreaker
This plant has the most blackening. It's also been the fastest growing and most bushy of the plants. I topped it last week but I guess I didn't take enough off and thought I must have accidentally fimmed it. However, it doesn't look like it's fimmed either. It looks more like deformed leaves coming through.

Strain 2
Honeysuckle
Has been the slowest grower. It took a week longer to sprout through the soil than the others (I thought it was dead but then it came through). I topped it last week and that part seems to be doing fine.

Strain 3
AK Auto
No topping etc, just growing as-is.

I'm starting to think the problem is not with the lights but with something else. I do have (but haven't used yet) some Advanced Nutrients Cal-Mag and some Liquid Silicone.

Any of you have any idea what's going on here? I'd appreciate the help

I've took some more pictures with the LED turned off but I have a cheap ass camera phone and it isn't showing the problem much better.

What is the medium or soil you are using?

Buba Blend said:

What is the medium or soil you are using?

Click to expand...

Oh my bad,

Started off in Biobizz light until around 2nd node, then transplanted to Canna Pro

Could be feeding to much. Could be nitrogen toxicity.

Buba Blend said:

Could be feeding to much. Could be nitrogen toxicity.

Click to expand...

I appreciate your response, Thanks. Should I switch to only giving them water, or back to what I was feeding them in wk3? I'm not experienced with nutes at all. If I roll back, when might it be safe to up the feeding again?

Also, if the problem is the nutes, would you recommended turning the other 50W COB back on?

I read up on nitrogen toxicity and the AK definitely looks like it has that claw affect, although its leaves are less black than the others.

I don't use that soil or those nutes so if it is N tox or to much of one of them that would be for someone else to help you with.
My guess would be to back off the nutrient use, it is always good to get a second opinion on this forum before deciding what to do. Good Luck!

Buba Blend said:

I don't use that soil or those nutes so if it is N tox or to much of one of them that would be for someone else to help you with.
My guess would be to back off the nutrient use, it is always good to get a second opinion on this forum before deciding what to do. Good Luck!

Click to expand...

Ok thanks for chiming in anyway. nitrogen toxicity could very well be the problem. Hopefully somebody else could give some advice on fixing it.

I forgot I even had a 4in1 soil survey instrument so I opened the box, turned it on for the first time and tested the soil. All 3 pots tested @ 6.5

I'm tempted to go buy some distilled water tomorrow to recalibrate my pH pen, then flush all 3 plants and double make sure the water with nutes is in the 6.5 to 7.0 range. A YouTube video suggested fixing nitrogen toxicity this way.

Does this sound like a good plan? I'm very new to growing and working with pH levels.

CryptoMcPoopypants said:

I forgot I even had a 4in1 soil survey instrument so I opened the box, turned it on for the first time and tested the soil. All 3 pots tested @ 6.5

I'm tempted to go buy some distilled water tomorrow to recalibrate my pH pen, then flush all 3 plants and double make sure the water with nutes is in the 6.5 to 7.0 range. A YouTube video suggested fixing nitrogen toxicity this way.

Does this sound like a good plan? I'm very new to growing and working with pH levels.

Click to expand...

You need to buy calibration fluid to adjust a PH meter, distilled water in a one gallon plastic jug from the store is not always a ph of 7 and can have a ph of 6 or less at times.
On you fertilizers the Advanced Nutrients Micro/Grow/Bloom sounds like it is similar to the general hydroponics trio. If they are similar they can be used but are better suited for growing in soilless mediums.

CryptoMcPoopypants said:

I forgot I even had a 4in1 soil survey instrument so I opened the box, turned it on for the first time and tested the soil. All 3 pots tested @ 6.5

I'm tempted to go buy some distilled water tomorrow to recalibrate my pH pen, then flush all 3 plants and double make sure the water with nutes is in the 6.5 to 7.0 range. A YouTube video suggested fixing nitrogen toxicity this way.

Does this sound like a good plan? I'm very new to growing and working with pH levels.

Click to expand...

get calibration solution for a few buck more. PH probes damage when trying to read RO/Distilled.

Plants look fine to me?

Buba Blend said:

Could be feeding to much. Could be nitrogen toxicity.

Click to expand...

N toxicity is the usual culprit for super dark green foliage. It's an easy fix. Flush the soil and give the plants a heavy foliar rinse with straight water. N in the plant is very water soluble and can be easily leached out with water (outdoor plants in the rain can even end up deficient).

That said, from what I can see in the pics they look perfectly fine. Maybe it's just the aforementioned low quality of the pics.

Hey homie, your soil is hot, flush it out with some 6.2ph water, run a gallon or two straight through the pot., cut back on all veg nutes temporarily.