First Time Grow, my plants are in trouble Need advice!

[herbologist_nad]

Hey so I am attempting my first grow and I am using the space in my closet. I am growing 8 plants of some grandaddy master kush. I am using grodans and a 400w light. It is in the grow stage right now and the light cycle is at 18/6. I water them once a day and I am having some issues. I started with 510 ppm's then moved to 640, then moved back down to around mid 500's. The plants don't seem very happy it looks like nute burn and I decided to flush the plants for 3 days but still don't seem very happy. The stems are purple and the leaves are yellow, lime green, and brown. I am asking if anyone would be able to tell me what I can do to turn these plants around. Thanks!

 

[bckushinator]

what the PH of your water ?? this could be having a major affect.. it does kinda resemble a bit of nute burn.. but i would check your water PH and soil ph tryin get em down to 6.2-6.8....using them rockwool cubes you have to be pretty precise on the nutes, ferts .....i would try a lil good R/O water with a lil epsom salt..hope this helps

 

[OctoberDee]

If you're using a hydro system you want your ph to be around 5.5 not 6. anything

 

[SSHZ]

Looks like a cal/mag issue. Add 10ml per gallon of water until problem solved.

 

[herbologist_nad]

The Ph levels of my water are always areound 5.6-5.8. I've been slowly decreasing the amounts of grow nutes, root accelurator. I've been putting in superthrive as well. Right now I put in 30 ppms of cal mag 40 of root accelurator, and about 200 of grow nutes. I've been watering them with pure R/O water 3 days out of the week seeing if any of it helps. the new growth seems to be coming in really nice but then the leaves start to turn lime green or brownish.

 

[OctoberDee]

Heat maybe? What are your temps??

 

[herbologist_nad]

when the light is on it's 74-80. when the light is off the temp is around 65. the humidity varies from 35-45.

 

[OctoberDee]

Sounds like temps are ok, maybe cut way back on the nutes and try just water for a few more days. Looks like nute burn, plus you said after flushing the leaves started to grow out proper. I'd try just water for like 5 days and then try adding smaller amounts of nutes than you've got going now. JMO