Unknown brown leaf spots. Please Identify

[Medical Widow]

Hello fellow tokers,

I just wanted to start off one of my first posts by saying thanks to the many experienced growers on this forum who have shared their grows and tips. I have learned much after reading from the best.

Ok, now lets get on to the problem I am having with my plants. Here is what I am running...

DWC (hydroton medium)
No known pests
GH Flora Series nutes 10ml/5ml per gallon (bloom/micro)
Day 13 of Flowering
OG Kush from clones
Humidity 35%-45%
temps 70-80 day 65 at night
rez(10 gallon) at 1300 ppm
rez temp at 74 degrees
ph at 5.9
600w HPS
4 plants

The problem that I have is brown/yellow spots on larger fan leaves. These spots are on fan leaves that are closer towards the bottom of the plant. Below the large fan leaves, some smaller leaves are all wilted looking.

From my pictures it is easy to see where the disease/difficiency is prevalent on the leaves. The first shot is of one of the fan leaves. In the second shot you can see where many of the leaves were affected closer towards the bottom and left side of the picture. Also, if you look closely you can see one of the wilted leaves(light green color) I was talking about at the bottom. The last picture is an unaffected area of the plant just to get an idea of how far it is into flowering. I was curious as to if anyone knows what this is, and if it is possible for me to fix it? If more pictures or detail is needed, let me know. Thanks in advance for any input you may have.

peace
-widow

 

[Weedninja]

Looks like an early-stage calcium deficiency. I would back off on the nutes a little before I started messing around with the cal-mag. Your last pic shows that your plants are suffering from minor nute burn.

What kind of water are you using, ie; tap, distilled or RO? PPMs or ec would be nice if it's tap.

 

[MynameStitch]

I need more information, just fill out the questions you did not answer here I don;'t know what your problem is right now you got to answer the questions first, more information helps out a lot. It could be from pH fluctuation problems, high level of micronutes, hard water damage. Calcium shows smaller spots not that big so from those pictuers it does not look like calcium issue.

HYDROPONICS/Aero Ponics/Coco/Soiless/

How long has this problem been going on?
Are you growing in a PVC grow tent? (example: Hydrohut or any other non brand tents)
What system are you running? (DWC? Ebb flow? Aero? Water Farm? Flood Tables? and so on...)
What STRAIN are you growing?
What was the establishing technique? (Were the seed or clone?)
What is the age of your plants?
How long have they been in there mixture they are in now?(coco,soiless etc..)
How tall are the plants?
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in?
What Technique are you using?
What substrate/medium are you using?(Hydroton, RockWool etc.)
What is the Water temperature?
What color are your roots? White? Brown? Are your roots slimy?
What Nutrient's are you using?(If growing soiless)
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful*
How often are you feeding? (If using soiless)
How often are you giving nutrients? (If using soiless)
If flowering, when did you switch over to using Bloom nutrients?
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)
What is the TDS/EC/PPM you are using?
What is the pH of the "Tank"?
Are you sure your calibration is correct on your equiptment?
When was your last watering?
What is your water temps?
When was your last feeding change? (ie. grow-bloom-micro-additional)
How often do you clean your system: example: Flush out water replace with clean water and nutrients?
What size bulb are you using?
What is the distance to the canopy?
What is your RH Factor(Relative Humidity)?
What is the canopy temperature?
What is the Day/Night Temp? (Include flucutaion range)
What is the current Air Flow? (cfm etc.)
Tell us about your ventilation, intake exhaust and when its running and not running ?
Is the fan blowing directly at plants?
Is your water HARD or SOFT?
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water?
Are you using water from a water softener?
Has plant been recently pruned, cloned off of or pinched
Have any pest chemicals been used? If so, What and When?
Are plant's infected with pest's

 

[Medical Widow]

Hey Stitch and Ninja thanks for helping me out. Sorry for not properly filling out the questions. Here is all the specs on my system.

How long has this problem been going on? First signs about 1-2 weeks, but recent spread within last 4 days
Are you growing in a PVC grow tent? (example: Hydrohut or any other non brand tents)-No
What system are you running? (DWC? Ebb flow? Aero? Water Farm? Flood Tables? and so on...)-DWC
What STRAIN are you growing?-OG Kush (indica i think)
What was the establishing technique? (Were the seed or clone?)-clone
What is the age of your plants?-1 Month from clone
How long have they been in there mixture they are in now?(coco,soiless etc..)-Hydro
How tall are the plants?All 4 plants around 30 inches
What PHASE are the plants in? (seedling, vegetative or flower) are the plants in? Flower Day 13
What Technique are you using? 1 plant was topped, no other techniques
What substrate/medium are you using?(Hydroton, RockWool etc.)-Hydroton
What is the Water temperature?-75 F
What color are your roots? White? Brown? Are your roots slimy? White
What Nutrient's are you using?(If growing soiless) GH lucas formula (twice as much bloom as micro)
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* 5ml/gal micro 10ml/gal bloom or until ppm reaches ~1400
How often are you feeding? (If using soiless)
How often are you giving nutrients? (If using soiless)-whenever nutes reach below 1000ppm
If flowering, when did you switch over to using Bloom nutrients?-Day 1 flowering
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) I mix the Flora SeriesMicro first and then the Flora Bloom
What is the TDS/EC/PPM you are using?1200-1500ppm
What is the pH of the "Tank"?Was around 6.3 last week but I got a digital ph meter and it is now around 5.6
Are you sure your calibration is correct on your equiptment? yes
When was your last watering?
What is your water temps? 75 degrees
When was your last feeding change? (ie. grow-bloom-micro-additional)-about 1 week ago
How often do you clean your system: example: Flush out water replace with clean water and nutrients?-its been two weeks....too many roots
What size bulb are you using?600 w HPS
What is the distance to the canopy?around 18inches
What is your RH Factor(Relative Humidity)? 35-45%
What is the canopy temperature?75-80 F
What is the Day/Night Temp? (Include flucutaion range)65(night) 80(day)
What is the current Air Flow? (cfm etc.)Not sure, have decent Honeywell
Tell us about your ventilation, intake exhaust and when its running and not running ?Cool air is blown into the grow room from an area of the house that intakes air from outside. Grow room ceiling is sloped, warm air exits out a normal water heater outtake. A little confusing, but anyway there is plenty of ventilation.
Is the fan blowing directly at plants? Yes two fans one blows towards canopy the other towards the stems
Is your water HARD or SOFT?-Hard
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? Tap water with 270 ppm
Are you using water from a water softener? No
Has plant been recently pruned, cloned off of or pinched?- No
Have any pest chemicals been used? If so, What and When?-No chemicals but used Mark's penetrator/zone spray two days ago as a preventative for powdery mildew
Are plant's infected with pest's? - No known pests

Any input that anybody has would be more than appreciated!! My ladies look sick, I really would like to help them out. If more pictures are needed let me know.

-widow

 

[Weedninja]

Someday I will learn to make people fill out the questionnaire.

2 things: the first is that your water is hard. GH makes a hard water formula micro, which is the first thing I would try because it's easier than buying an RO unit or buying distilled water.

The 2nd is that you need to change your res. Period, end of story. It's causing your tds to build up and it's causing pH creep. If you have trouble getting to it to change it, try to siphon it out with some plastic tubing.

Good luck

 

[SmokeSumThin]

it looks like something cal/mag would help. Some plants need it, some don't. I had the same exact problem during my last run and it helped the problem not spread. and now im going to use it on every run. Some runs i might not use alot and some runs i might need alot. Everything looks fine except the res temp, looks like it could come down bout 10 degrees or so. the first thing to do is flush then change res!! I would drop down ppm's to bout a 1000 to see if that burning stops also then you can go up from there. If your water is indeed hard use the hard micro instead. Might solve the problem without the calmag hope that helps you out.

 

[Weedhound]

I'd ask you several things......first one being are you positive there are no pests?

Second I COMPLETELY AGREE with weedninja.....you need to change the res. ASAP. If you think you are having root issues now wait until you are halfway through flower and your roots start to rot then. You'll be screwed.

Also now that you have a regular ph meter you're going to be reading and keeping that ph adjusted all the time now aren't you? So that will rule out any ph issues that may have assisted your problems along. I personally consider 6.3 "stepping outside my comfort zone" so would consider you to have had an abnormal ph for awhile. Again....as WN said.....change your res.

 

[islander420]

Yup. Looks like calcium deficiency. Just throw some cal/mag in your mix and everything should look better in a week. This happens frequently with system using RO water since it removes the calcium from the h20.

Yup, slight nute burn. Try backing off about 100ppm. Make sure to keep a grow journal for each strain so you can improve next time around. Makes it a lot easier trying to remember what you forgot because you were too stoned.

Nothing to worry about, plants should be fine. I've had much worse and was still able to recover.