Ca / K def vs. Fungus

[space.pussy]

How long has this problem been going on? About two weeks.
What system are you running? NFT + a few plants in perlite/vermiculite buckets. Problem appears on all the plants.
What STRAIN are you growing? Sweet Afghani Delicious
What was the establishing technique? Clones
What is the age of your plants? Fourth week into flowering. Veg: 28 days; flower: 27 days.
How tall are the plants? 40cm / 1′4″
What PHASE are the plants in? Flowering. (4th week)
What Technique are you using? NFT
What substrate/medium are you using? Plants are in rockwool cubes in a GroTank (NFT system). I have three other plants in a mix of perlite/vermiculite.
What is the Water temperature? 19°C - 22°C / 66°F - 72°F
What color are your roots? White, not slimy at all, show perfect health.
What Nutrient's are you using? Metrop MR2, Metrop Amino Bloom, Metrop CalGreen
What is the TDS/EC/PPM you are using? EC 1.5mS so I guess that'd be 960 ppm
What is the pH of the "Tank"? 5.8 (fluctuates between 5.7 - 5.9)
Are you sure your calibration is correct on your equiptment? Definitely, I check it every week, esp. now with these problems popping up.
When was your last watering? NFT pump runs all the time, the ones in perlite I've last watered two days ago.
When was your last feeding change? Three days ago
How often do you clean your system: Once every week
What size bulb are you using? 400w HPS
What is the distance to the canopy? 30cm / 11 in.
What is your RH Factor(Relative Humidity)? 35 - 45%
What is the canopy temperature? 28°C / 82°F
What is the Day/Night Temp? Ambient temps range from 19°C / 66°F (night) to 28°C / 82°F (day).
What is the current Air Flow? Box exhaust: 340m3/h so that's about 200cfm + 1000 m3/h / 590cfm circulation fan.
Is the fan blowing directly at plants? yes
Is your water HARD or SOFT? Mediocre, it's EC is about 0.3 mS / 192 ppm
What water are you using? pH adjusted tap water
Has plant been recently pruned, cloned off of or pinched? I have removed some leaves to reduce evaporation and thus prevent mold.
Have any pest chemicals been used? Previcur against fungus (as a precaution), a week ago.
Are plant's infected with pest's? No bugs, caterpillars or anything visible.

This is my first post to this forum, though I've been lurking in the shadows for a while now, so High Everyone, hope my other posts will not be about my problems but rather about successes. It's also my first grow indoors.

I'm suspecting the cause of my problem could be a combination of Calcium / Potassium def, but foliar feeding the plants some CalGreen (has Calcium in it) has not helped, neither has adding some PK 13/14. What I'm really worried about is whether this could be caused by some kind of fungus? Or is it just a deficiency?

The problem appears on all my plants and is not local (appears on older leaves mostly, but on some younger ones as well). Also what puzzles me is that some of the leaves curl under (please see attached pics).

Also please take a look at the last picture and note the brownish color at the tip of the pistils. Is this something to worry about, possibly a start of bud rot?

Any suggestions will be appreciated greatly.

EDIT: It seems I may not post attachments / URLs, so please take a look at my gallery.

 

[MynameStitch]

The one picture without the hps light on looks like a nitrogen problem.

Is there anyway you can upload some more pictures without the lights on? The lights hide the problem very well.

I would have to see more pictures to see what the problem is....... but from the looks of it, it might be a nutrient related problem.......

 

[space.pussy]

Thank you, MyNameStitch for your reply! I have added a few more shots with the lights off. I've tried taking some pictures without flash, but they didn't turn out too well. I picked the information-richest ones, so you don't have to look through a whole lot of images that don't say anything about those plants.

Please do have a look at the first picture showing Four stages of brown pistil coloration and state your opinion about it, I'm getting worried it's something serious. So far, I've come up with a possible cause: I do foliar feed the plants about an hour before the lights go off (to keep humidity down) and i use about 3 - 5 drops of liquid dish soap per liter as a wetting agent (that'd be about 15 drops per gallon). So it could be that the dish soap has something to do with it OR -- which i believe is more likely and also definitely more horrifying -- the increased humidity might have made it possible for fungus contamination.

What do you think?

1. Four stages of brown pistil coloration




2. Suspected Ca deficiency




3. Top left probably N deficiency, bottom left Ca deficiency(?)




4. The above in greater detail




5. Leaf discoloration / necrosis occurance on one of the plants in perlite.




6. Possibly Ca def. What do you think?


Thanks for any help, it will be appreciated very much.

 

[space.pussy]

Any ideas?

 

[Whobdobub]

Im having the a somewhat same issue right now.

Eventually my leaves turn completely brown and dead, dry as a bone.
At the tips of the leafs when they are green and dont have any spots yet, i have what looks like a fungus type mold growing from the tip of leaf inward.

But on top of it, my leaves are also looking like yours which just started along with my reverse osmosis.
So i think your having cal/mag problem, which i was told would happen to my plants after switching to RO.