Clones with brown patches need help with diagnosis

[DWCPortland]

I recently purchased Obama Kush Clones they were 21 days old when I got them. I have had them for one week. So they are not at about 28 days. This is my second attempt at a grow my first time ended badly with bad clones and bugs.
They have brown patches that feel and look like dead leaves. What can be causing this? Is this a deficiency, stress or something else?

MY System:
Nutrients: General Hydroponics - Using their chart at week 3. Which is 10ml/gal of Miro 10ml/gal of Gro and 5ml/Gal if Bloom
Buckets: 4- 5 gallon with a control
Water level: about 2 inches below net pot system running 13 gallons total
PH: PH has ranged from 5.5-6.0 it has gone up progressively since I got the plants on 9/11/14.
PPM: 850-1050. The PPM seems to fluctuate when the light goes off.
Water Temp: 67 it was 77 but just added a water chiller
Water Chiller: 1/10
Tent: 4ft x 4 ft
Inside Tent Temp: 73-77
Humidity: 50-56
Humidifier: 3 gallon cool mist
Light: MH 600 watt 18/6
Ventilation: 450 CFM inline fan to cool light
AC: 5000 btu running directly into top of ten
Fans: one 16 inch oscillating fan as well as a 6 inch fan by the ac hose
Airpump: 35 watt with 2 inch air stones in each bucket
Water pumps: Main pump is 950 gph that controls the system and one 185 gph pump running to water chiller.

 

[NuttyProfessor]

was any thing spilt on them , nutes ect ? , looks like something was spilt and the light cooked it

 

[DWCPortland]

It is possible that something splashed from the buckets when I had to move them however that is very improbable. Especially since this is occurring on three of the four plants. Thank you for the input and taking the time to reply.

 

[c526]

I like the setup,why such an advanced setup,if your just starting??

R.O or tap water?
ph is a little high,few years ago when i played with the dwc/rcdw I started at 5.6 and let it drift to 6.1, there is nutrients that your not picking up,if you let it sit and stay at 6.0,some nutrients must be picked up in the 5.5-5.6 range

pic#2 is a phosphate issue,pic #3 is a phosphorus,manganeese and calcium issue

oh---those leaves will never recover,watch as the new growth comes out

 

[DWCPortland]

Thanks for the input.
I did use tap water. To answer your question I put a lot of effort abd money into the system because I wanted to do it right and not halfass it.

However, when I look back and see what the level were at for the last few day my PH has ranged from 5.5-6.0 it has progressively increased over the last 5 days. Today it being at 6.0. Would PH still be the issue?

Thank you again for taking the time to read and reply.

 

[c526]

bring the ph down slowly,little at a time,or it will have an effect on the leaves,.3-.5 per day
how are you adding back to the system??pure water?half addback??

for right now there isnt anything I would change until you give it a minute,get ph in range and see.the food maybe sitting there,but the plant cant eat it.

 

[DWCPortland]

I have not added to the system yet. My water levels are not changing much since the roots just hit the water yesterday. When I do add back into the system I will add according to how my PPM levels are I would assume, and how much nutrients the plants are absorbing. I may lower the ph to see if that helps.

Thank you

 

[DWCPortland]

How can I combat a phosphorus deficiency? I think that is my problem. I did a water change and added the correct nutes. The problem is not getting any better but worse. I have read online that I can use the Bloom nutrients to help with this issue. If that is true what could you recommend about how much I should add into the system. Any input is greatly appreciated. Thank you.

 

[c526]

still on the tap water??
do you know the ppm oF the water?? I use tap(when rain water runs out) and it is high 355-ppm,I have to adjust my feed schedule

any chance you can get 0ppm R.O? I think that will help until you gain some experience

yes you can use the bloom,but again,Until you know whats in the water,its a growers call.
I am not familiar enough with your nutrients to tell you exactly what to add.

If you can get a sample of water,your local county extension office will be able to test it and tell you what is in it,cost is minimal,under 15(in my area)

I'll see if I can get some more peeps to look at thread,to be honest I only have a couple of years dwc/rcdw
I gave it up,to many hassles for me,I still grow with water,but now im a set it and forget it system.

Remember man,the shitty leaves will get worse,not better,they never will

 

[budstud]

Plant is deficient in P, K, and Zn. https://boards.cannabis.com/attachm...sted-leaves-some-tips-curled-down-phchart.jpg

 

[DWCPortland]

I am using my tap water. I think I will test to see what is in it and make sure of the ppm of the tap water as well. I have not tried to used RO water for the system since my last time growing the tap water seemed to work out fine.
However I live in a different county now and that all may have changed.
Thank you for your input again!

 

[DWCPortland]

Just checked my water and you are dead on it was at 230 PPM. Now I am looking for some R.O. to replace it with and drain and refill the system with the correct levels. I have obviously not been giving enough nutrients to the plants. Thank you again for all the help.