? Problem w my DWC grow at it's 3rd week of Veg . . lookin bad . . please help

I have got 1 plant (cross between Blueberry & white widdow) that I am growing in DWC. It is at 2 plus weeks of vegetative stage. Using House & Garden nutrients. I just noticed the leaves are getting kinda brittle and have these dark blotches on them. Also, if you will note the pic of roots and they have just started coming out a green color. The pic on the right is the best showing the dry leave w dark splotches. Its the best my cell phone camera would do. I am thinking maybe phosphorus deficiency, but could really use some advise. Thanks so much!

I'm definitely not an expert at this point, but from what I've learned / read, the green in your roots may be algae and typically results from your root system being exposed to light. It's a risk with DWC setups, but can usually be addressed with filling in your net pot past any of the portholes or covering the entire top of your growing apparatus except for the plant and stalk.

The green roots issue can be treated with H2O2 but I don't know the exact concentration to use (though I've seen posts that recommend .5 - 1% concentration (take total volume of water in your system in ml and multiply by .005 or .01 to determine how many ml of H202 to add)).

The leaf issue may be a separate issue involving your nutrients or it may be linked with the root issue - I don't know. So, like I said, definitely not an expert but I saw that no one had posted an answer for you yet and wanted to give what help I could. Hopefully someone else will see this thread, too, and can chime in to confirm or correct my post. Also, you may want to move or recreate this thread in the Marijuana Plant Problems forum, it may get more traffic there...

Good luck!!

-TiRx

...I just realized from your pictures that your bucket is translucent... that's a *big* no-no with hydro / DWC. You've got to get that bucket blacked out or replaced with one that doesn't transmit light or this will continue to be a problem.

Yup a clear res is a big big no no. You have algae growing in your res now, and it is robbing your plants of oxygen. Get a light proof container.

And a fresh res. That looks nasty. Poor plants.

What are you feeding it in terms of EC? PH?

I had to leave for a while and saw these responses. Thanks so much guys. I did not know about the clear container. Will paint the outside black right away. firsttimeARE, I do not know about the ec, but keep ph right around 5.8-6.0. I will do anything and everything to get this right, so once again, thank you. I will get back w you all. Do u all think that it is the container and not Phosphorus deficiency?

id flush with plain ph'd water. fill a bucket with ph'd water and submerge your roots up and down rinisng them lightly replace your res with a fresh batch off mild nutes around 2-250 ppm's it looks like some sort of lock out has growth slowed

you can throw peroxide 3% at a tsp per gallon that should clear up the rot.
others say more but had a mild case when temps got warm in beging of my grow and this did the trick

Testone, gonna flush w plain (ph balanced) water & will add hydrogen peroxide per ur recomendation of a tsp per gallon. After this, will put them in a fresh batch of nutes. Will do this now and get back w you all. Thanks again.

Another thing to consider is the res temperature. Make sure it doesn't get over 76 f which is still pretty hot. You should aim to keep the res temp around 68-72 f. You can use frozen water bottles to keep the temperature down. Also local aquarium stores sell thermometers for approx. $10 and they are worth the investment. You should def use Hydro Peroxide and maybe follow the "8-Step Remedy". They also make beneficial bacteria that combats stuff like that but I have never used any of that.

Good luck!

Your problems stem from the root zone. Good luck with the h2o2. I know people use it to prevent root rot, but a lot of people are unable to actually cure root rot with it. I think it is more useful in flood n drain and nft where you roots aren't submerged in a bucket of water 24/7. IN dwc I have just heard too many reports of it not clearing up root rot, and benes finally had to be used. If it works, great... if it doesn't you could potentially spend weeks continuously adding it only to eventually figure out it isn't working and your shit still isn't growing. Also, the h2o2 people use is something like 29-34%; the 3% kind commonly sold at walmart and grocery stores most likely won't do diddly fuck and you might be better off just adding plain clorox bleach to your res every 3 days. Dutch Master Zone and Nutrilife h2o2 and SM-90 are popular.

https://www.rollitup.org/hydroponics-aeroponics/94811-al-b-faqt.html for more info on using h2o2 and good info in general.

What I can say is the success of your grow... whether you are going to get any bud to smoke or not... hinges on whether or not you can get this under control. Fortunately, it's not expensive or hard, and it doesn't take a long time to see recovery if you do things correctly. The biggest problem you have is light leaks and that is easy enough to fix. But you still have to do something to stop the algae and shit from progressing. The following process is something I have done more than once, and it works for me.

I would simply flush the net pot and roots with a small splash of bleach (or h2o2, zone, etc) in tap water, and then make a new res and pick up a $15 bottle of aquashield; will last the entire grow. Get as much slime and algae off the roots as you can with your fingers. You can gently tug on the roots to slough off any dead ones. If that doesn't fix it (which it probably will), add worm castings aka ancient forest humus (I never had to do this... see https://www.rollitup.org/dwc-bubbleponics/361430-dwc-root-slime-cure-aka.html for details). Your green roots won't fix themselves, but new growth should be white and you should see new growth in a couple days after inoculation. No need to use ph water, ph is only important for nute uptake. Anything you are doing that doesn't involve nute uptake does not have to be at any particular ph.

Anyway, try the h202 and if that doesn't work, use benes.

A couple things to remember about your dwc bucket...

• PH and PPM measuring pens/meters are a per-requesite and an upfront investment for dwc. Once things begin to fall out of suitable parameters, changes happen quickly when roots are submerged in a bucket of water. You need measuring equipment to make sure you maintain the proper ph and nute strength, which is obviously vital.
• Light proof - wrap it up with silver bubble wrap from home depot (reflectix) and duct tape. Insulates, light proof, reflective, affordable, easy to get... what more could you want? I guess it could be kinda hard/awkward to steal, which might be considered an area they could 'improve' on.
• Temps - 68* I swap a 1L bottle of ice every 24 hours to maintain this temp. If you run benes you should be safe in the low 70s.
• PH - 5.8 if your ph isn't the majority of the time between 5.6 to 5.9 in early veg, you are risking lockout. I prefer to be more like 5.9 to 6.0 in flower.
• Bubbles - I believe the recommendation is a commercial air pump, something like 1L/min per gallon to reach maximum dissolved oxygen saturation.
• EC - Nute strength based on size/condition of roots, not leafs; .5 or .6 for a healthy plant around the size of the one in your picture (250 - 300ppm if meter is x0.5 scale, most likely it is if you got it from the United States). Maybe a little lighter until you see new root growth.
• NPK - make sure you don't stack up on one element like P or cal/mag because too much of one element can/will lock out other shit. For example, people like to make a coctail of bloom boosters and hardeners and sometimes use so much PK they lock shit out.
• Beneficial Microbes (benes) or Sterile - Even with all of the above correct, some people can still get dirty water. You might have to continuously use either h2o2 or benes. I use Aquashield for benes. Some people substitute bleach instead of h2o2, but it's generally considered sketchy. You can probably get away with just pond-zyme from petco for general maintenance when you have no root problems.

As for your leaf spots, those won't heal but new leafs should be healthy... just fix the roots and they will be fine. I would actually experiment with foliar feeding nutes since your roots look pretty much out of commission at the moment and the plant is showing deficiencies.

Thanks Malevolence, for the advice. It looks as though is getting worse. I painted my res bucket black, flushed the roots in ph balanced water, then added the nutes and about 30 mg's of hydrogen peroxide was last. My grow bucket is only 4.0 gallons. Could it be Phosphorus and/or magnesium deficiency?
Up until a few days ago, this was a beautiful plant. It is just 2 1/2 weeks into veg. Please, any help would be appreciated. Is looking worse?
Can there be no light whatsoever in the bucket? Do I need to tape the little gap between res & cardboard holding pot?

Thanks all. I didn't think about the water temp. Was at 80 deg until i put a frozen bottle of water in it about 10 min's ago. I also put in about 30 mg's 3% hydrogen peroxide. It is looking worse this morning. Maybe the water temp had a LOT to do with it? Too much H2o2? Here are some more pics. thnx

Thanks for the advise. My res temp was at 80deg!! Got it lowered.

I flushed the roots w bleach & water, painted my res black, lowered the water temp and things are starting to turn around. This is my first DWC grow. I had been using Coco Not soiless medium and am now trying to switch over to DWC. thanks again all