Magnesium?? (pics)

Have 8 plants that are starting to have light green to yellow new growth and the oldest leaves on the bottom are yellow with green veins and dying. On the most dead ones, it seem the veins toward the tip are no longer green. My best guess is that they need magnesium but this is my first grow and I really have no idea. I've also read that the old leaves will fall off anyway.

Here are the details:

8 fem White Widow

400w hps about 2ft above

temp is usually almost 80F but varies 70-90

they are about 6 weeks old

planted in approx 2 gallon pots

water every couple days when soil is dry to about 2in down using tap water that has sat for 24-48hrs.

have been on 18/6 cycle.

originally planted in MG 3mo release soil then transfered soil and all into bigger pots with non fert soil.

have used zero nutrients other than what was in the MG soil, and havent shown signs of problems until now

have a bottle of fox farm big bloom i plan to start using next watering.


Please let me know what you think the problem is and the best way to fix it. Switched to 12/12 today if that changes anything. Also, brown spots in pic are unrelated, they are from touching a light a while back. I'm broke so I dont have a pH meter. Thanks for any help.

that foxfarm big bloom should be used in conjunction with the other foxfarm nutes. the NPK of big bloom is only 0.01-0.3-0.7. i used the foxfarm trio; grow big, big bloom and tiger bloom. here is the feeding chart i use. its my first time using foxfarms so im at week 3 and using half strength. i will be at full strength soon. next year i will get the solubles trio and use those also.

http://www.foxfarmfertilizer.com/soilfeed.pdf

It could be a number of things. I would suggest adding Cal-Mag into your watering. Keep the temps stable and hopefully with the cal mag it will all work out.

What are you growing in i.e. tent, room etc?

unity said:

What are you growing in i.e. tent, room etc?

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Ive sectioned off a 3.5X4.5 room in the attic with plastic. vents out the top and in the bottom through a duct tapped into the house

Also, Cal-Mag something I can buy pretty much anywhere?

Your gonna have to order it online or go to a hydro store for that

Dude honestly all that new growth looks great unless your not showing all the plant. tiny leaves like tyhose cut off and keep growin reallt that looks fine atleast the 1st pic. You could start using some cal-mag though it wont hurt.

haze2 said:

Dude honestly all that new growth looks great unless your not showing all the plant. tiny leaves like tyhose cut off and keep growin reallt that looks fine atleast the 1st pic. You could start using some cal-mag though it wont hurt.

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The rest is fine, I was just trying to show how the newer growth seems to be more yellow than the rest of the plant. Don't remember it being like that before.

So, Ill get some cal-mag and I have big bloom. If I get tiger bloom to go with that should I be good until im done?

Are you growing organically?

haze2 said:

Are you growing organically?

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Not trying to, just dont really know what I'm doing since its my first grow. Why, is FF all organic? Would I be better off with something else?

tdiddy said:

The rest is fine, I was just trying to show how the newer growth seems to be more yellow than the rest of the plant. Don't remember it being like that before.

So, Ill get some cal-mag and I have big bloom. If I get tiger bloom to go with that should I be good until im done?

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ive never used cal-mag, i gota look it up and see what it is.

in my above post take a look at the fox farm feeding schedule. about half way through flower it says to add some grow big for a couple of weeks. its higher in nitrogen so it will help keep your vegetative growth for a little longer. im not saying you absolutly need it but i going to use it. its just my 2 cents.

Yeah Id get that and you will be fine, Im growing in FFOF and some pro-mix bx and both seem to work real nice if you stick with soil get some unsulphured molasses and feed 1 tbsp per gallon. It will improve nutrient uptake it improves flavor, smell and weight.

Sounds good, thanks guys!

Indeed!!!!!!!

OK, added cal-mag, molassis, tiger bloom, and big bloom. We'll see how things go. Has been great up to now but the lower leaves are starting to die off pretty quickly. I've read diff things but I think I will add these every 3rd watering. Was going to do every other but the guy at the hydro store said 3rd should be better.

I am using the same nutes as you as well as big bloom. Great line up of nutes dude

Roots Organics is also bomb diggity nutes.

tom__420 said:

I am using the same nutes as you as well as big bloom. Great line up of nutes dude

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haze2 said:

Roots Organics is also bomb diggity nutes.

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Well I hope I starts working soon, the lower leaves seem to be getting worse still... On a brighter note, starting to have hairs show up!

mine looked like that, I put some lime juice in and used my regular micronute formula VF11 and it went away. just cut the lime and squeeze some juice in, not too much, just some. lime to lower the ph