Phosphorus deficiency? I think! experienced growers please help!!

Ok so im at about week 4 or 5 in veg. I thought this was a phosphorus deficiency. So I've added more. I'm not sure if i correctly diagnosed it. my PH is 6.5-7 Im using Fox farm grow big 2 tsp/gal. in 1/3perlite 1/3 vermiculite 1/3 sphagnum peat moss. Is it possibly the PH is too high to absorb the Phosphorus. The edges of the leaves are dry and brownish like brittle paper if this helps.! Any help from experienced growers would be greatly appreciated!!!!

thanks in advance!!

growin4myhead said:

Ok so im at about week 4 or 5 in veg. I thought this was a phosphorus deficiency. So I've added more. I'm not sure if i correctly diagnosed it. my PH is 6.5-7 Im using Fox farm grow big 2 tsp/gal. in 1/3perlite 1/3 vermiculite 1/3 sphagnum peat moss. Is it possibly the PH is too high to absorb the Phosphorus. The edges of the leaves are dry and brownish like brittle paper if this helps.! Any help from experienced growers would be greatly appreciated!!!!

thanks in advance!!

Click to expand...

May be nute burn or pH problem. I'm gonna say probably nute burn.

doc111 said:

May be nute burn or pH problem. I'm gonna say probably nute burn.

Click to expand...

Are you checking pH before or after you add nutes? Sphagnum can lower pH. You can try adding a bit of fine dolomite lime to buffer against too low of a pH.

nute burn?



There's a good chance that this bud was subjected to nutrient solution burn. These symptoms are seen when the EC concentration of hydroponic solutions is too high. These symptoms also appear when strong nutrient solution is splashed onto the leaves under hot HID lamps, causing the leaves to burn under the solution.
Note that if the plants never get any worse than this here, then the plants are probably just fine.
Many hydroponic gardeners see this problem. It's the beginning of nutrient burn. It indicates that the plants have all the nutrients they can possibly use, and there's a slight excess. Back off the concentration of the nutrient solution just a touch, and the problem should disappear.



Figure 5 is definitely an over- fertilization problem. The high level of nutrients accumulates in the leaves and causes them to dry out and burn up as shown here.

You must flush with clear, clean water immediately to allow the roots to recover, and prevent further damage. The find the cause of the high nutrient levels.

doc111 said:

Are you checking pH before or after you add nutes? Sphagnum can lower pH. You can try adding a bit of fine dolomite lime to buffer against too low of a pH.

Click to expand...

before and after it does not vary by much at all. I doubt its nute burn, i only feed them like oncce a week. and im using the recomended amounts and after adding more ferts the problem hasnt worsened. But again I need advice from someone who actually knows!!!! ive googled my head off and I've come to most of the same conclusions as the people on here!! I just need to know for sure!!!! again thanks to all who reply!!!!!!!!

look into an ozone( air quality) problem, maybe its not real great circulation in there jus a thought man even tho you prolly got a fan old air can be trapped in the room and reek havok

kho20 said:

look into an ozone( air quality) problem, maybe its not real great circulation in there jus a thought man even tho you prolly got a fan old air can be trapped in the room and reek havok

Click to expand...

Ventillation should be good, I have a 12" outside air inlet with a carbon filter as well as a carbon filter circulating old air to the outside. and a fan blowing on them........i think that should be good enough.

hmm.......

growin4myhead said:

Ventillation should be good, I have a 12" outside air inlet with a carbon filter as well as a carbon filter circulating old air to the outside. and a fan blowing on them........i think that should be good enough.

hmm.......

Click to expand...

that should be good then well scratch that i guess

Okay............here are the most recent pics just took them!

anyone? im trying to correct this asap!

id say nut. burn also.

What's the humidity in there like? If it's not that then it looks like some sort of deffiency. Not p though.

Im starting to lean towards nute burn myself, should i flush them or just ride it out? Ive had 2 successful grows b4 and never run into this. hmm wierd.

growin4myhead said:

before and after it does not vary by much at all. I doubt its nute burn, i only feed them like oncce a week. and im using the recomended amounts and after adding more ferts the problem hasnt worsened. But again I need advice from someone who actually knows!!!! ive googled my head off and I've come to most of the same conclusions as the people on here!! I just need to know for sure!!!! again thanks to all who reply!!!!!!!!

Click to expand...

Even the most experienced growers can't tell you 100% what's wrong and any one who tells you they know for sure is full of shit. I was trying to ask a couple of questions to help you try to rule out the obvious. And it still could be nute burn, the signs that you have point to nute burn. Once a week may be too much to feed your plants. Anyway, Good luck with your grow.

well backing off the nutes gonna feed straight water for a week or two and see what happens. will post an update at that time. thanks to all who helped!

I had this same exact problem in my current grow. All of my plants did this until I transplanted them and switched soils. They just didn't like the premium potting soil I had them in (which contained built in ferts). Your plants look identical, I would say stop with the Grow Big, just use regular water.

from experience when one of mine got nute burn the leaves that were affected didnt repair them selves the parts that showed it jus didnt get worse and new growth was good again jus a thought so you dont expect those leaves to return to what they were

nute burn ... slow down on how much your giving them and dont over delute the water with chemicals use what is said on the container or even a littleless

yea its nutes. It was said somewhere but they are not going to repair and watch the new growth to see if you have fixed the problem.