black spots?

[kamezzle13]

after i checked out the guide and didnt see a pic or description of this prob, i tried doing a search and nothing seemed to show up (search terms were pretty common). i checked out the post labeled brown spots below, and mine look much dif, so here goes. ill have a pic up momentarily

SOIL:

How long has this problem been going on? 2-3 days
What STRAIN are you growing? bagseed (unknown)
What was the establishing technique? (seed or clone?) seed
What is the age of your plants? 1.5 months (est)
How long have they been in the soil mixture they are in now? 2 weeks
How Tall are the plants? about 36"
What PHASE (seedling, vegetative or flower) are the plants in? Veg
What Technique are you using? (SOG, SCROG etc) LST, just to keep the height down
What size pots are you using? (Include how many subjects to pot) 3 gallon, 2 plants, only one affected
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) 2 parts shultx potting soil, 1 part vermiculite, 1 part perlite
What Nutrient's are you using? shultz 10-15-10
How much of each nutrient are you using with how much water? 1/3 strength at most
*Knowing the brand is very helpful*
How often are you feeding? once every other watering, sometimes two waterings
If flowering, when did you switch over to using Bloom nutrients? n/a
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect)n/a
What is the TDS/EC/PPM of your nutrients used?
What is the pH of the "RUN-OFF"?
What method of pH test was administered? Using Strips? pH pen?
How often are you watering? 2-3 days, when soil dries out
When was your last feeding and how often are you feeding? 2 days, has only been fed a few times
What size bulb are you using? CFLs, 1x42 watt, 2x42watt 2X27watt (blue)
What is the distance to the canopy? 2-5 inches
What is your RH Factor? (Relative Humidity)
What is the canopy temperature? 75-80 degrees max
What is the Day/Night Temp? (Include fluctuation range) stays around 75, may drop to 65 at night
What is the current Air Flow? (cfm etc.) unkown, tall pillar style fan blowing on it 24/7
Tell us about your ventilation, intake exhaust and when its running and not running ?
Is the fan blowing directly at plants? indirectly
Is the grow substrate constantly wet or moist? when watered, let dry out inbetween
Is your water HARD or SOFT? HARD (before put thru brita)
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? Tap thru brita filter
Are you using water from a water softener? no
Has plant been recently pruned, cloned or pinched? pruned some dead leaves
Have any pest chemicals been used? If so what and when? no
Are plant's infected with pest's? havent seen any



She was going through terrible ph probs a few weeks ago, until i repotted her in some good soil - was in miraclegro with a ph of 5 before, but when nutrient lockout began, i corrected the problem, and put her in new soil that had a ph of 6.5ish. The leaves that showed the ph problems from before began to yellow then die after spots began. I thought it was only the older leaves, but this morning i confirmed it has started on growth since the repotting. There is another female in the same pot, and does not seem to be showing the same probs. Im about to take her out of her chamber and take a few pics, will post soon.

 

[kamezzle13]

Here are some pics. The last pic is of the smaller girl in the same pot. I didn't notice any spots on her until i went to take pics, then i found a few. These plants were given to me, and we grown from bag seed, i believe they are two different strains, possibly why one is being attacked more then the other. I haven't really noticed any insects or bugs, until today i saw one single tiny bug, i checked all the other leaves and couldn't find anything else. The spots seem to be forming on the older leaves that grew during or right after the ph probs, but hadnt started this until 3 days ago

Any help is greatly appreciated. Thanks in advance

 

[kamezzle13]

i ended up treating her for nutrient deficiencies because the healthy leaves just didn't look green enough either. Instead of straight brita water, i fed my normal nutes again at 1/4 strength (2nd time in a row feeding) with half brita half tap water. I figured since ive been giving it brita, its missing out on is Ca and Mg.

the leaves greened up tremendously and it seems to have slowed down the rates at which the spots were appearing, although in between watering it had gotten worse. I do believe i gave her a little bit of nute burn, next time i'll water with no nutes, and then resume to feeding her 1/2 strength nutes instead of the lower dosage she was receiving.

 

[kamezzle13]

so i fear both the plants are a few days from being dead now. i thought the issue was getting better, the healthy leaves had looked like they greened up, but the spots now have taken almost over the whole plant. they get black spots, start to yellow, and within 1-2days drop off. I mean, if i gently shake the plant, the affected leaves start to fall off by themselves, not to mention if i touch them.

any ideas? i watered her again today with some nutes (skipped them on the last watering). I've been mixing brita filtered water with tap water and a small amount of vinegar to get the ph down to where it needs to be. i wanted to see what would happen if i went away from the brita water completely, but im in the process of moving, and wont be able to try that (or transplant) until the next couple of days. I just fear she will be dead by then. any help is greatly appreciated.

 

[kamezzle13]

i wanted to add that ALL of the leaves are curling UP, not sure if this helps, im trying to find my camera to post some newer pics, but i fear i've packed it by accident

 

[mitchyboy89]

All this time and no experienced gardener has helped you? wow..

 

[kamezzle13]

Was it the vinegar i used to lower the ph? I only used a couple drops per gallon of water, but thats one thing that did change from healthy to sick...

 

[kamezzle13]

so i figured it out. i finally got a chance to take it out and repot. I had tested the soil yesterday and the ph was still right, so i wasnt sure if i was going to find the cause. Immediately after i pulled it from the pot, i noticed the roots had grown like crazy, too much. the whole sides of the 3 gallon pot were held together by nothing but roots. They looked healthy, nothing was rotting, but there was more roots then soil in alot of places. I repotted with slightly higher concentration of soil (as prepared with vermiculite and perlite) to give the roots something to grab onto besides themselves.

i'm not sure if it was because i had recently upped the feeding schedule or because couple weeks ago i cut away the outer roots, and stimulated the root growth suddenly?

im going to proceed as usual from here, starting with a healthy watering and feeding. while i was moving, i missed watering for two days, and i thought it was going to be dehydrated due to how light the pot felt, but those roots sure grabbed every last drop and held moisture great. I now see why letting the top soil look completely dry in between watering works under the surface.