patchy brown leaves - please help

[MomentOfMadness]

Hi, a few of my plants have developed these brown dots on their leaves, does anyone know what might be causing it, and how to fix it?

The problem is in the lower 1/2 of the plant starting with the oldest fan leaves. faint yellow dots appear, then the middle of these turn brown. This seems to spred over the leaf. The photos show the leaf in different stages of the problem.

I tried giving one of the plants epson salts 4 days ago. It dosn't seem to be getting better, but not much worse either.

I have had a bit of trouble getting the soil to absorb water (from the beginning), it mostly seems to run throught he soil without wetting it, it seems that eventually it is reabsorbed from the bottom.

Indoor soil grow.
The plants with this problem are just in potting mix (some of the others have wormcastings mixed in)
The PH has been 6.7 - 7.0
I'm using Tap water with a PH of 7.0 (usually left siting for 24hrs before using)
Plants are 5 1/2 wks old
I have been using organic fertiliser NPK = 8.3.6 every second watering.
I am using a 400watt HPS light about 14inches from the plants.
Its a closet grow I have two fans running one is pulling air from outside the closet.
The lights are on 24hrs, and the temperture is ranging from 79-83 degrees. Im not sure of the humidity level.

Any ideas???

 

[dankbud420]

i have the same problem with my hydro plants. people have told me it was a mag. diff. but im not for sure hope u get help with this problem

 

[THE BROTHER'S GRUNT]

You need to get your PH down to about 6.5 and by the looks of your plants it's nute burn.

 

[MomentOfMadness]

Cheers,
I folar fed a couple more with epson salts this morning, hopefully that does the trick. Most of the plants have nitro def, could it still be nute burn if they are def in nitrogen?

 

[dankbud420]

nute burn can still play a roll whats the ph at now and what nutes ru using/ what kind of soil? cut off all the old dieing leafs and base what ur doing on ur new in coming leafs. if any thing i would start flushing with some distilled water and stop the epsom salt and start floral spraying with straight water. give it about a week or so and see if u c a diff.

 

[Sticky_Budz]

Hey MM i just wanted to add that you might want to transplant her into a bigger pot I'm sure she is root bound you could put her in a bigger pot with some nice new soil which would help you with your problem good luck hate to see sick plants hope she gets better soon peace

 

[SensiGuy]

Im having a similar problem but when I checked my ph is was fine. I got a ppm meter and it read about 1800, i checked general hyrdoponics website and it said the water should be between 1500-1600 with there three part system, I made some fresh water with nuts and it said 1800 too! I thought maybe the meter was off but why the browning plants, and why when used correctly could i get nut burn???

 

[lyfr]

ive heard people mention to mix GH slightly under whats recommended.i used it at recommended strength in my ebb&flow for two grows so far without any problems that i knew of...but i didnt have a ppm meter then either.well see what happens next one. goodluck and happy trails