Discoloration etc. on leaves, can't diagnose it myself

[stealthpackage]

Hello all, I'm on my first grow, and am having a small issue with some discoloration on the leaves of a couple of my plants. I'm doing LST on a three bucket DWC system in a closet. 600w HPS, Holland Secret nutes by the book, and BioBizz root juice to supplement root growth. The temps in the room hover at around 79-83 fahrenheit, I try to keep the temps in the buckets stay below 72ish, but they are known to go up sometimes, as I just use frozen pop bottles to keep the buckets cool, and have to change them out frequently which doesn't always happen. Humidity stays between 47-52 percent which should be good. I check my pH at nute changes and once in between, and two days ago I noticed that the pH had gone up to approx. 7-7.5, so I adjusted it with pH down, which I know isn't really the best thing to do, but this time it will have to do. Now that the background is laid down, on to the pictures.


Thanks for looking and please offer any input you've got! Thanks a lot!

 

[sproutco]

I think the nutrients are on the strong side.

 

[stealthpackage]

Ah, ok. That makes sense, as there is something I forgot to mention in my first post... I added 1 L of 1/2 strength nute solution to the buckets the same day that I adjusted the pH, which I have now read might have been higher than it should have been. Next time I will do 1/4 strength nutes and see how it goes. Thanks for your input, sproutco! Anyone else??

 

[powdergreen]

how old are they veg or flower. trhey do look dark green like nit toxic i agree with spoutco back off on the nutes. do you know your ppm

 

[stealthpackage]

In the pics, they were mid-3rd week veg. I am using the recommended amt. of N, but again, it may have been an issue with me feeding them those 1/2 strength nutes on Wed. They are now at the very beginning (changed the nutes moments ago) of their 4th and last week of veg. So dark leaves are a sign of N toxicity? Thanks again for the help
EDIT: ALSO, will be borrowing a tri-meter from a buddy and will let you know the PPMs

 

[Sleepy]

shoot for 5.5-5.8 with your pH.

mix nutes and let them sit out before adding them to the bucket/reservoir.

check the pH before dumping it in...adjust again if necessary.

this will get worse. get your pH in range first!

EDIT...i just looked at the other pictures in your gallery...if they are the same plant, they are suffering from nutrient lockout caused by pH way out of range.

lets see a current shot of the plant(s)...

were you able to clean that gunk out of the rez/hoses yet?

this will compound your problems and only make things worse...

clean everything and start with a fresh pH adjusted reservoir, no nutes for a few daze...

does the rez smell yet?

clean clean clean...then keep it clean.

get that pH in range and keep it there...

best of luck.

 

[stealthpackage]

Sleepy, Thanks for your input, but I have a few issues with what you've said. First, everywhere I've seen recommends not mixing the nutrients at full strength, and I tend to agree there. I've also seen good results with another grower mixing nutes the way I do. Also, I am checking pH very frequently now. The first time the plants were put in the buckets, I checked pH just after mixing nutes in the water, and did the same the first time I changed out the nutes. The 3rd week, I did the same and the results were fine, but the difference is that I noticed these problems mid-week. Now, something to take into consideration is that I USED TO clean my buckets with bleach before mixing the nutes. Although I rinsed and wiped the bleach away, I'm considering the fact that the bleach (highly basic) is what raised my pH a few days ago and caused those problems. The plants were in those buckets 3 days after noticing the problems. I topped them with some plain pH balanced water to lower the nute concentration 2 days ago, and changed the nutes altogether tonight. Also, I didn't use bleach to clean the buckets, I used hydrogen peroxide, which should be fine. The buckets don't smell, and the gunky lines are no longer an issue, as I switched root stimulators. (On that note, I'm beginning to think that shit might not be worth it anyway, but my roots do look amazing) Pictures to come...

 

[stealthpackage]

Here are some shots of the plants and some of the leaf discoloration. It's still not affecting that many of the leaves, but there are a few more than when I started this thread. Hopefully this nute change I did will have some positive effect on it. I might use Clearex for a couple of days, but I'm still thinking about that.
Here's a shot of the right of the growroom, the plant on the right hasn't been trained in any way, but the smaller middle one and left hand one have been LSTed. I plan on scrogging the middle girl.


Here's a shot of the left side.


This leaf in the pic below is on the left hand plant in the picture above, it's the only one like that.


Below is a pic of what the leaf damage typically looks like.


That pic isn't that great, so check the ones at the top if you need to see it. Let me know. Have a good day, all

 

[MTF-Sandman]

What are the odds of hot spots from that foil tape being the cause?

 

[stealthpackage]

There's a chance of that, and I haven't considered it yet. That would be too bad, as the main purpose of that tape is to reflect light from the reservoirs to avoid heating the water, but I do know that the undersides of the leaves are very sensitive and can be damaged from the light. Again, I've seen it done this way, though, even with higher wattage lamps, and no problems tere.

 

[stealthpackage]

Also, what is a safe way of lowering the pH in one's reservoir? I have read that pH down and pH up solutions are a less than healthy way of doing it. I've read that soil growers can add vinegar or lemon juice, but that it's not good for hydroponics. If anyone's got a good tip for this, let me know.

 

[stealthpackage]

If there's anyone out there that has seen this kind of leaf damage before, chime in. This'll be the last bump for the thread and I'd really like some help! Thanks a lot!