Advice on slight yellowing of new growth

Jojo420420

New Member
Hello All,
First grow, and I am 5 weeks into veg and I have slight yellowing of new growth. Is this normal and does my plant look healthy?
 

mikeyboy2121

Well-Known Member
Looks like you need to raise the light a little. If you see yellowing on the tops but the lower half looks fine it's probably light or heat stress. Check out the ridges of your top leaves if they're pointed up that's another sign. Raise your light 8 or 12 inches and see if it greens up.
 

Jojo420420

New Member
Looks like you need to raise the light a little. If you see yellowing on the tops but the lower half looks fine it's probably light or heat stress. Check out the ridges of your top leaves if they're pointed up that's another sign. Raise your light 8 or 12 inches and see if it greens up.
I have the LED lights fairly far away from the plant and when I put a light meter right at the top of the canopy I am between 25k-35k lux so I was thinking my light is good, but as I said this is my first grow so just trying to stay on top of things. I just ordered a blue lab ph and ec meter to ensure appropriate nutrients but that won’t be in till late this week.
 

mikeyboy2121

Well-Known Member
That's too close. 35-40k is my lux for peak flower. Over 40k I start to see problems. In veg I aim for 20-25k max or I'll start seeing tops that look like that.
 

buyyouabeer

Well-Known Member
I have the LED lights fairly far away from the plant and when I put a light meter right at the top of the canopy I am between 25k-35k lux
This is perfect at the maturity level you are at; I would seriously not worry about it. You do not have light bleaching.
 

mikeyboy2121

Well-Known Member
Jojo, look at this guy's thread. He's a first timer also and his plants are what you should be striving for. Notice the tops are nice and green at around the same maturity.

 

Jojo420420

New Member
I’ll raise the lights. I have another plant that’s a little smaller and has some yellowing but not as much as the other. May be due to the height difference.
 

mikeyboy2121

Well-Known Member
Just remember, you can get by with relatively low lux for veg. Worst that can happen is the plant stretches a little more for the light and that's how you know you can bring it a little closer. Too close and you'll get yellowing and very short internode spacing like you see currently. Read the plant and let it guide you. In general though, anywhere from 15-25k and you should have happy plants. In flower once they stop stretching (3 weeks) the leaves will harden off and you can up the intensity to 35-40k.
 

Jojo420420

New Member
Just remember, you can get by with relatively low lux for veg. Worst that can happen is the plant stretches a little more for the light and that's how you know you can bring it a little closer. Too close and you'll get yellowing and very short internode spacing like you see currently. Read the plant and let it guide you. In general though, anywhere from 15-25k and you should have happy plants. In flower once they stop stretching (3 weeks) the leaves will harden off and you can up the intensity to 35-40k.
A little update. It appears it wasn’t light bleaching. I received my combo Ph EC meter and my runoff water was very acidic. I flushed it with pulverized lime and ph 7 water to raise the ph and I am back on track. I was wondering how it got so acidic, and this morning I tested my nutrient solution (first time since flush) and the ph was good until I added the nutrients and it dropped the solution ph to 4.5. Now I know I need to increase the ph of nutrient solution after adding nutrients to water. Hopefully this will put me back on track without any major issues in flower.
 
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