Yellowing at bottom/brown edges during vegetation

[LamestTomato]

Hello all, this is my first time posting here and I must say that the forum of this site is really helpful when read! I have a somewhat urgent question about my plants health. It's in the vegetative stage currently and has been for 50 days since first breaking the soil. The soil is of an organic base, which sits in a 1 gallon pot with a teaspoon of bone and blood meal mixed in with 20% pearlite. My light comes from a 12 watt "daylight" cfl.
Just a few days ago, the cotyledons started to wilt, which is expected, not long after that the first "true" leaves (the ones that grow from between the cotyledons in the early stage) began to yellow out and now that I've checked on it today the edge of one leaf had brown edges. My light cycle is 18/6. Ph is about 7
Any light on the situation will be appreciated, I just want to rule out the deficiency/toxicity it may have. Thanks, I will post pictures soon.

 

[CO Finest]

What kind of water you using and what PH is it? How often are you watering? pic would help. Are you using nutes?

 

[LamestTomato]

hey co finest, my ph meter says it is 6.9

 

[LamestTomato]

Oh, and I water when the soil is dry down an inch. I've heard of nutes, just never bothered to get any because I didn't think I needed them.

 

[David Bowman]

to

I think your slow growth is mainly due to lack of light, a 12 watt CFL is not nearly enough light to grow even one plant, you need at least 2-3 times that much light to get decent growth and you could go all the way up to 100+ watts if you really want to see it explode in growth. After 50 days of vegging, I can imagine that your soil has exhausted its supply of nutrients and it is now time to feed them to your plant. The yellow lower leaves look like N-deficiency to me and I believe that a little feeding with a high N fertilizer will go along way to improving your grow.

 

[LamestTomato]

Hmm, well I did some research and people said that a cfl that puts out 1600 Lumens should do nicely during veg, which my bulb has that much intensity. Just checked the area where I transplanted the root ball from a jiffy cup into this new pot, the soil around the stem is as hard as a rock. I immediately watered this spot a little, to maybe loosen the soil from the root. Maybe a blood meal tea could act as fertilizer? Today, the yellow leaf has wilted even more.

 

[David Bowman]

For a decent grow, you need at least 2500 lumens / sq. ft. for vegging, 3500 lumens / sq. ft. for flowering. Another way to measure how much lighting you need is via watts, for a decent grow you should have at least 50 watts / sq. ft. As long as you get some N to your plants, it really doesn't matter what you use.

 

[LamestTomato]

I will look into it, thanks I'll update it's condition later if anything changes.

 

[LamestTomato]

Well, sadly enough, I checked it this morning to find that the leaves droop even more with the bottom fan leaves more yellow. A little bit of twisting has happened.

 

[David Bowman]

If you have already feed your plants a little food, wait for a few days to see how it reacts to the feeding and that should tell you if you need to feed more or less next time. You can't always expect changes overnight with soil, time is needed for the plant to take in what it needs and distribute it around the plant.

 

[LamestTomato]

But the suspense is unbearable! lol. But could it be due to root lockout caused by ph fluctuations? Just got a reading of 7.1, which in soil it grows best when at a ph between 6.5 to 7.

 

[David Bowman]

It's possible as you are indeed correct about the proper pH for cannabis in soil. But 7.1 is not that far off for N to be utilized by the plant.