Sick plants, possible phos def

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Hi,

I'm attaching a pic of one of the affected girls. There are a few more and they're showing the same symptoms. Week 4 flower. Temps are down at 62 degrees ambient so I thought it was just cold stress and then the leaf curling, yellowing beyond light bleaching, and necrosis kicked in. I did a search and the closest match I can find is phos deficiency.

I'm growing in soil, using fox farm nutes, 6.5ph feeding around 1200-1500 PPM, CO2 at around 800 PPM, 68F, 50% humidity.

Any help? I want to catch this before it turns really bad. Maybe I should do a Tiger Bloom (fox farm bloom) foliar just in case, couldn't hurt right?

Thanks!
:)

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1200-1500ppm is burning them. That is far too high for soil IMO. I rarely go that high in Hydro anymore.
 
Others will chime in soon enough to correct me if I'm wrong, but I believe that purpling on the leaves is a magnesium deficiency. They can give you advice on what to do exactly, but I'm pretty sure if it is a megnesium deficiency, they'll tell you to use some cal-mag.


***edit***
Just checked out a few pics and it doesnt look like mag deficiency at all. More like you said, phosphorous.
 
Thanks, getnasty, Ogkushman

I've mostly been doing around 1200 ppm and the 'official' fox farm nute feeding program suggests 1200-1500 on light days and 1500-2200 on heavy days. I don't want to start feeding them less when it could be a nute deficiency, know what I mean? Maybe you'd be willing to share more on why you think it's burning them. Getnasty, I don't think its mag def either, I've been adding calmag to the reg schedule.
 
Looks like they may be a little hungry at week 4. Mine look like that from less N. But, they do need P when they are in flower. I vote a light feeding and watch. Greenest of mojo to you.
 
If it is nutrient lockout from excess fertilizers, then deficiencies may show up. Either way I would flush with a high dose of phosphorus (pH down). Put some pH up in, and add a bunch of down to get it where you need. Then water them on straight pH water and see if growth improves.

*cold temps can also lockout phosphorus...
 
In that second pic the pot looks small, so it might be a case of a root bound plant
 
I am inclined to agree with OGK as 1200-1500 is very high for the plant to be deficient from a lack of food. It seems like I have heard someone say that FF nutes tend to get some salt build up in them over time. If you have been slamming them with a high rate of nutes for a while now, I would bet that you have a salt build up that is locking out at least the P if not other chems as well.

On the other hand, that bag is not real big for the size of the plant. If you vegged that plant for a couple months before flipping then you could have a root bound issue. If it is root bound then you should be able to see the roots starting to protrude around the edges of the bag at the top(I would think), and be able to feel considerable root mass around the skin of the bag.

I am still more inclined to think the first. I would say do a real good flush as OG said and go from there. I am not a soil guy so I'm not sure but I would think that if it is root bound that the level of feeding you have been doing would have eliminated the issues associated with that. :)
 
Thank you Hushpuppy, OgKushman, Ozzydiodude,

Before I read your messages I started to clue into the possibility that it was nute lock out due to too much nutes because it couldn't be def at those nute levels so I did a big flush with clearex.... they're pretty saturated right now so I was going to wait a few days for them to dry out before doing a feeding 700ppm this time....... over watering can be a bad too, so I think that's the right call... what do you think? I'm at day 31 flower right now....

I transplanted these girls into 2gl containers when they were in 1s right before starting flower so I don't think they're root bound.

I think they might be showing improvement already since their flush yesterday....
 
oh yeah, before I realized it could be nute lock out, I did a foliar with 1 tsp/gl of Grow Big and 1 tsp/gl of Tiger Bloom...
 
I don't think 2 gal containers are nearly large enough for those plants. I would think you almost have to be root bound if you are in 2 gal pots.
 

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