HELP Big Prob.

[Help]

OK, I am using an EBB and Flow system, the nutrients are changed and the plants are washed every two weeks, the nutrients being used are GH (Grow, Bloom, Micro), the plants look great in Veg but once they are 2 – 3 weeks in Flower they begin to turn yellow (the tops first) with the veins staying green. The tips are pointed down with a little burn at the tip and once the leaf begins to die the tips turn up.

 

The nutrient strength is as the manufacturer recommends (1200 – 1400 PPM / American System) the temp in the room is 70 or so and the water temp is the same. They feed for 15 min. every 4 hours only in the light period.

 

I think it is an Iron or Magnesium deficiency, but I just do not know and need help. Thank you so much for the help.

 

http://i2.photobucket.com/albums/y42/helpprob/DSCN3804.jpg

http://i2.photobucket.com/albums/y42/helpprob/DSCN3805.jpg

http://i2.photobucket.com/albums/y42/helpprob/DSCN3806.jpg

http://i2.photobucket.com/albums/y42/helpprob/DSCN3810.jpg

Edited March 16, 2005 by Help

[truthteachingtransformation]

Hi-

I'm new here, but grow my own in Oregon. It looks to me like possibly a nute lock-up, not enough light, and maybe lack of nitrogen. This could be a direct result of a nute lock-up...Just a guess. Happy growing.

[Guest Eikel]

Hi Help,

 

Well I'm still on my first grow, so this is "out of the mouth of babes" per-se.

 

The pics of the leaves on the plant with the "light-green" tinge to them looks exactly like my plants did.

 

I fixed this by dropping the ph of my nutes/watering-solution from 6.7 to 6.2 - the plants greened back up and continued strong. I'm growing mine in CoCo as a medium, so if you're using a Hydro system you may want ph to be lower (5.5-5.8).

 

What is your ph? Most nute problems are caused by ph being "out-of-range".

[jackfrost]

g'mate. welcome to ozstoners.

 

 

 

First of all - pull out plant and check roots for root rot (roots should be ivory white with no brown spots.) If thats not the problem then....

 

IMHO it needs more floodings. Flood and drain = lights on 12 hours = 6 feeds two hours apart for 15mins each or 18 hours light on = 6 feeds three hours apart.

 

No feeding at night ----> try 1 feeding to remove toxins roots release.

 

In flore change water once a week and top up dailey

 

The 3 part GH nutes are good, but you have to use the 8 week flore table provided by General Hydroponic, not what it says on side of bottle - this table of nutes will gradualy decrease N and increase PK, right up to the last week of flore where your using no N.

 

Another thing you should not use GH alone but as a part of a system ie 3part nutes, floralicious,Kabloom,Florasheild,diamond nector,Chi etc....see there web site.

 

Ive used General Hydroponics for years with no problems at all. Its buffers the water so good i hardly ever have to look at PH.

 

Jack

[quizywig]

Id agree with jackfrost about not enough feeding times i run mine 15min every 1.5- 2 hrs, depending on the weather/heat and one in the middle of the dark cycle, also set the timer so the plants get a feed at the immediate start and end of the daily light cycle, Ph around 5.5-6.0

[F420]

Its not his flood timings,

 

I use flood and drain and mine is set to run for 15 minutes every 4 hours, and I dont get problems like that.

 

In my sig is some links for ph charts and also for nutrient problems.

However I think its PH.

 

also this is a good one with pics-

 

http://www.marijuana-seeds.net/Thanks/ThankYou.htm