Yellow Edged Leaves

[Cannaculture]

Thanks to those that are reading this and can offer their advice.

I'm currently just under one month into my first grow. I've chosen Liberty Haze as my first girls to experiment with and up until a few days ago everything was going Jim Dandy. However, my first sign of trouble arose when the leaves began curling up along their length.

A quick search and I put this down to either a bit too much water or the fact that the fan had accidentally been left on too long and it was a reaction to this. After cutting the fan out for a couple of days normality seemed to return in the main.

Then I encountered my newest problem - a slight yellowing towards the outer edges of the leaves and an almost complete yellowing of the smaller leaves growing from the lower portion of the stem.

Another bit of research later and I think i've narrowed it down to one of a few issues but wondered if any of you sagacious lot could perhaps point me a bit more in the right direction. So, i'm thinking it is maybe either over watering, N deficiency, pH trouble, or, and maybe it's just me, but the yellowing coupled with some prominent black running through the centre of the leaf could be a P deficiency. I've also flirted with the idea that it could be a lack of Mg.

By way of some additional info here's my noobs guide to my set up -

One 400w HPS inside a cool tube
Currently in one gal smart pots
bio mix all mix soil
day time temp fluctuates but i've maintained it between 80 and just below 90

Up until monday i'd not used any nutes and only given them water as I thought the soil would be good enough to sustain them for 2/3 weeks. On monday though I gave them a 1/4 strength dose of Canna Vega.

I've watered them about every other day, each receiving around a third of a pint each.

I hope the pictures come out clearly enough to show the problem.

Any help or advice is greatly received and I apologise if this is going over old ground.

 

[bigcheese510]

sounds like youre on the right track. it looks like a nitrogen def. id feed them and even add some cal mag and theyll bounce back within a week or so.

 

[Cannaculture]

sounds like youre on the right track. it looks like a nitrogen def. id feed them and even add some cal mag and theyll bounce back within a week or so.

Thanks BigCheese! I was more inclined to the N def. Do you think three weeks without food was too long to go and was a 1/4 strength feed far too little?

P.S. is your avatar a young Mr Stanhope?

 

[bigcheese510]

could be, im not familiar with the soil youre using. id give them a full dose feeding and see how they react. nah its booger from revenge of the nerds

 

[Cannaculture]

could be, im not familiar with the soil youre using. id give them a full dose feeding and see how they react. nah its booger from revenge of the nerds

Thanks again. I'll full dose them tomorrow and see how they go. I was just a bit scared to give them the full whack first go but maybe under did it too much.

And the clue to it being Booger is name written clearly underneath the picture! Ever the observant one!

 

[LexLuthor]

I'd use a half dose, but thats just me. I never give plants that small the full label dose. I wouldn't use Ca-Mg either, I never needed Ca or Mg supplements when growing in soil. Make sure your base nutes and soil are low in Ca before you supplement Ca-Mg. Also, drop your temps below 80, try to keep them in the mid 70's if possible.

 

[Mogrow]

yes lower the temps to mid 70's if you can.
them babies look like they could use some thing, the structure is still good with the leaves still pointing somewhat up.
try this
1 gallon of good water, 1/4 cup alflafa meal, couple tablespoons aloe vera juice, couple tablespoons kelp meal, bubble for a day or 2. cut till it looks like drinking tea then foilar the shit out of them at lights out, soil drench the rest.
if you don't have these ingredients , get them, much better than bottled nutes. imho.

 

[MakinGoo]

She looks a bit hot & hungry.. I'm sure ur gunna see some changes b'cuz u already gave her some food

 

[caregiverken]

I'd use a half dose, but thats just me. I never give plants that small the full label dose. I wouldn't use Ca-Mg either, I never needed Ca or Mg supplements when growing in soil. Make sure your base nutes and soil are low in Ca before you supplement Ca-Mg. Also, drop your temps below 80, try to keep them in the mid 70's if possible.

Cal mag cant hurt though can it?
I use a little when I see yellow..along with some N
it seems to work out the lock sometimes

 

[Cannaculture]

Thank you all for your advice! I didn't go with the full dose feed, just stepped it up from a 1/4 to 1/2. I'm wondering if anyone could suggest an amount that a plant in a one gallon pot would take to water roughly. I give them a 1/3 of a pint each, which result in a small amount of run off out of the bottom, but worry it may not be enough.

Also, thanks for the info on temp! Will make getting that 5/6 degree drop my priority.

 

[LexLuthor]

Cal mag cant hurt though can it?
I use a little when I see yellow..along with some N
it seems to work out the lock sometimes

IMO it depends, I use GH Micro, Bloom + Epsom salts, which gives me a 1:1 N:CA ratio, now if my soil has Ca from limestone and bone meal, plus my base nutes have sufficient Ca, I would over do it with a Ca-Mg supplement, which could cause lockouts of all sorts.

I've never used Canna nutes so thats why I said to check his base nutes and soil to see how much Ca is available to his plants. Depending on his situation, it might be necessary to use Ca-Mg, or he might not need it. I was just giving my experience in soil.

 

[caregiverken]

Thank you all for your advice! I didn't go with the full dose feed, just stepped it up from a 1/4 to 1/2. I'm wondering if anyone could suggest an amount that a plant in a one gallon pot would take to water roughly. I give them a 1/3 of a pint each, which result in a small amount of run off out of the bottom, but worry it may not be enough.

Also, thanks for the info on temp! Will make getting that 5/6 degree drop my priority.

I learned to feel the weight of the pot, to know how much water to give..
If it gets too dry, water can just run Through .
I need to pick up the pots, to know if they are getting enough water

 

[LexLuthor]

Thank you all for your advice! I didn't go with the full dose feed, just stepped it up from a 1/4 to 1/2. I'm wondering if anyone could suggest an amount that a plant in a one gallon pot would take to water roughly. I give them a 1/3 of a pint each, which result in a small amount of run off out of the bottom, but worry it may not be enough.

Also, thanks for the info on temp! Will make getting that 5/6 degree drop my priority.

When I use soil, I water til there is about 10-20% run-off, but I water when the buckets feel light, about 50-70% lighter then when saturated with water. Basically, when I water them I lift the bucket to see how heavy it feels, then I won't water again until it feels at least half as heavy. Every environment and grow is different, your just gonna have to dial-in your watering/nutrient schedule.

The temps and RH are an important factor when it comes to how much moisture and nutrients the plants need. During veg, temps can go to the low 80's with RH around 60-65% and they will grow fine, but during flower you want temps below 80 (mid 70's) and RH around 50%. Later in flower I really don't like the RH to go over 50%.

 

[jkbeing]

^^^right on.
Keep your temperature lower!

 

[Cannaculture]

The temps and RH are an important factor when it comes to how much moisture and nutrients the plants need. During veg, temps can go to the low 80's with RH around 60-65% and they will grow fine, but during flower you want temps below 80 (mid 70's) and RH around 50%. Later in flower I really don't like the RH to go over 50%.[/quote]

Thanks again everyone. I did think it'd just be a case of feeling the weight but wondered if there was a general rule of thumb to go by as a yard stick.

I'm going to aim to get the temps lower and water a little more with maybe another one or two feeds before up planting to the 3 gallon pots.

And excuse my ignorance, but what is RH?

 

[LexLuthor]

RH = Relative Humidity. It basically tells you how much moisture is in the air relative to the temperature. Air can only hold a certain amount of moisture, and the hotter the air, the more moisture its able to hold.

Do you have a thermometer with a hygrometer on it?? You can get the digital ones at Lowes/Home Depot for about $15. The thermo shows temps and the hygro shows RH.

 

[LexLuthor]

Oh yeah, watering when your pots feel light IMO is the rule of thumb.

 

[Cannaculture]

RH = Relative Humidity. It basically tells you how much moisture is in the air relative to the temperature. Air can only hold a certain amount of moisture, and the hotter the air, the more moisture its able to hold.

Do you have a thermometer with a hygrometer on it?? You can get the digital ones at Lowes/Home Depot for about $15. The thermo shows temps and the hygro shows RH.

Thank you Lex very much. I've already ordered myself the thermo/hygrometer you recommended from Amazon. I knew all about checking humidity levels in the reading I did before I got these on the go only once you get the girls planted and they take off it's amazing how much stuff I forgot to keep tabs on.

I gave them a 1/2 dose of the calmag too which, in hindsight and from reading your advice, may not have been necessary but i'm hoping the reduced dose won't do anything detrimental at least.

Thanks again and I'll update this in a few days or so if there's been an improvement in the hope it might help others in the future.

 

[Rootbound]

What is the PHand EC of your feed water going and then what is PH and EC at runoff?

 

[Cannaculture]

What is the PHand EC of your feed water going and then what is PH and EC at runoff?

Rootbound, the pH I keep at around 6.2-6.8 and the EC i'm only going to be able to test for the first time tomorrow as Amazon f'cked up my order for the meter and i've been assured it'll arrive then.

What is a good EC level and the best way to lower it if it is too high?