Do i need more blue?? diy cxa3070 build

[jay5coat]

Hi guys, just switched to a diy cxa3070 3k panel running 27 watts ser square foot and having issue. I also have one of the same plants under 2x 5k cxa3070's that looks fantastic as did all of the others untill i put them under the 3k lighting. I see that the 3k cxa's only have 10% blue and 15% to 20% is best from what have read, should i add some blue stars or 2x 5k cobs to each side? i thought i had a mag deficiency but they are all the same age and were potted up at the same time and the plant under 5k does not show any of the same symptoms as the others under 3k lighting. these plants are very good but finicky, I am at a loss any help is appreciated.
mother plant

the rest

 

[Mechmike]

That looks more like a magnesium deficiency than a light specific issue.

 

[captainmorgan]

So the mother is on veg time and the others are 12/12?

 

[jay5coat]

Everybody is on 18/6 right now, basically all the plants are the same age and have been treated the same just under different lighting. I thought it was mag deficiency also and I did a foliar spray of Epsom at ¼ tsp per gallon and a week later a feed with the same amount. They look a little better but its still progressing on the plants under the 3k lighting. By the way soil pH is 6.6 to 6.7 using Ro water with calimagic. Ro water is 7.1 ph. Using ffof soil and nutes but have only ferted a few times at ½ to ¼ strength.

 

[SupraSPL]

SDS did some re-figuring and put the blue percentage for the 80 CRI CXA3070 3000K at 13-14%. That should be OK for most varieties and your internode length looks OK by my measure. What I think you are looking at there is just the plant adapting, and they will push through it and resume normal growth. Some of my ladies get burned a bit when I switch them from the veg room to the flower room but they adapt and push through it no problem. The way I see, anything we do to try and "correct" the situation will likely turn a non-issue into a real problem (eg flushing, watering in epsoms etc).

Lately I have been increasing the intensity in the veg room and now it is easier for them to adapt to the intensity when they get into the flowering room. I guess the best thing would be if I could dim the flowering room for the first week or so.

 

[stardustsailor]

Everybody is on 18/6 right now, basically all the plants are the same age and have been treated the same just under different lighting. I thought it was mag deficiency also and I did a foliar spray of Epsom at ¼ tsp per gallon and a week later a feed with the same amount. They look a little better but its still progressing on the plants under the 3k lighting. By the way soil pH is 6.6 to 6.7 using Ro water with calimagic. Ro water is 7.1 ph. Using ffof soil and nutes but have only ferted a few times at ½ to ¼ strength.

(...)
Calcium Deficiency

Problem: Signs of a cannabis calcium deficiency can be hard to pin down since calcium deficiencies are often accompanied by magnesium, iron, and other deficiencies. However, some of the major signs of a calcium deficiency are in the leaves which will display dead spots, crinkling, spotting, or small brown spots. Another sign of a cannabis calcium deficiency is new leaves will appear small and distorted with curled tips The insides of the plant and well as the flowers/buds may show signs of decay. Roots may show signs of bacteria and may be dying off or be under developed.

Boron Deficiency

Problem: Cannabis leaves and roots show abnormal and slowed growth when showing a boron defiency. The first signs of a cannabis boron deficiency is abnormal or thick growth tips. New leaves may display chlorosis (yellowing of leaves). Stems may become rough or hollow. The plant may look like it has a calcium deficiency because boron is needed for the plant to properly use calcium. New growth is affected the most, and may look like it's been burnt or scorched.

(...)


The reason you're noticing the symptoms under the 3K light is quite simple.
3K has more " red band" output and less " blue band " output than 5K.
That means some metabolic differences ,already.
Under the 3K light,plants have way higher photosynthetic rates more than under the 5K.
Higher anabolism ,in biology terms.
Thus producing much more biomass daily.
Thus greater needs,than those under a 5K light.
Under the 3K light,plants need regular feeding.
And a correct pH .

The 5K light promotes protein synthesis (like chlorophylls ) ,
but it has an inhibiting effect regarding PS rates.
Plant metabolism "slows down" under 5K light.
So ,while it is a great light ,to enhance chlorophyll biosynthesis ,
it won't actually aid the plants to grow ( as in ":increased anabolism " ) .

So :
1) Fix your pH. Soil pH of 6.6-6.7 is high enough.Lower it around 5 -5.5
2) FEED them.

 

[SupraSPL]

I agree, they will be some hungry ladies. But FFOF is composted organic soil that should have decent fertility, so tinkering with its PH might not be advisable. The PH readings of organic soil can be very misleading. I have not checked the PH of my runoff or soil for years because the PH of my water is "normal" ~7. But if you are using water that has a strange PH that could cause a problem even in organic soil. It sounds like your water PH is all good though.

 

[jay5coat]

Ya I am not going to mess with my pH, anytime it has every gone below 6 ( using tap water) I have had serious lockout issues. I have never had a pH issue using ro water. I just flipped them to 12/12 so I'll see how it works out. Other than the ¼ strength Epsom I gave them last week I have done nothing different than my other grows with this strain.

 

[Mechmike]

Ya I am not going to mess with my pH, anytime it has every gone below 6 ( using tap water) I have had serious lockout issues. I have never had a pH issue using ro water. I just flipped them to 12/12 so I'll see how it works out. Other than the ¼ strength Epsom I gave them last week I have done nothing different than my other grows with this strain.

I was having some similar issues earlier this year. Calcium and Magnesium lockouts. Adding Fulvic acid made a huge difference. Fulvic acid acts as a chelating agent making immobile nutrients like calcium and semi-mobile nutrients like magnesium available for uptake by the plant cells. Ful-Power by BioAg is a highly purified form which has none of the minerals that raw powdered for does. I prefer the powdered form because it's a fraction of the price of Ful-Power.